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Results for “tumor location”

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At least 19 recordsLinked to original sources

PubMed2003

Intra-mammary tumor location does not influence prognosis but influences the prevalence of axillary lymph-node metastases.

BACKGROUND: The number of axillary lymph-node metastases is not only a function of disease progression in primary breast cancer, but is also influenced by the intra-mammary location of the tumor. Nevertheless, the prognostic role of the tumor site is discussed controversially. The objective of this study was to analyze the impact of primary-tumor location on axillary lymph-node involvement, relapse, and mortality risk by univariate and multivariate analysis, in patients both with and without systemic and loco-regional treatment. METHOD: Retrospective analysis was conducted on 2,414 patients at the I. Frauenklinik, Ludwig-Maximilians University, Munich and Berlin-Charlottenburg, who underwent R(0) resection of the primary tumor and systematic axillary lymph-node dissection (at least five lymph nodes resected) for UICC I-III-stage breast cancer. Patients with unknown tumor site, multifocal tumor spread, central tumor location, or tumor location within 15 degrees of the border between outer and inner quadrants were excluded from the study. Median observation time was 6.7 years. RESULTS: The primary tumor site was within or between the medial quadrants of the breast in 33.6% of the patients ( n=810) and in the lateral hemisphere of the breast in 66.4% ( n=1,604). Tumor size, histopathological grading, and estrogen receptor status were balanced between patients with lateral and medial tumor location. Metastatic axillary lymph-node involvement was significantly associated with a lateral tumor location ( P<0.0001). The mean number of axillary lymph-node metastases was increased by 29% in cases with lateral tumor location (2.2 vs 1.7, P=0.003). In a multivariate logistic regression analysis allowing for tumor location, estrogen receptor status, grading and tumor size, tumor location was confirmed as a significant risk factor ( P=0.02) for axillary lymph-node involvement. Tumor location, however, did not correlate with either disease-free survival (DFS) or overall survival (OS), by univariate (DFS: P=0.41; OS: P=0.57) or by multivariate analysis (DFS: P=0.16; OS: P=0.98). CONCLUSION: We conclude that there is no sufficient evidence to support any independent prognostic significance of intra-mammary tumor location in early breast cancer. However, medial tumor location may lead to the underestimation of axillary lymph-node involvement.

Analysis of Variance↗

PubMed2002

[Prognostic value of tumor location of urothelial tumors of the bladder, after total cystectomy].

OBJECTIVE: Comparison of the various treatment protocols for bladder cancer requires identification of survival prognostic factors. Some clinical parameters, such as tumour sub-site, have still not been studied. The authors therefore analysed the prognostic value of this factor, in combination with known prognostic factors, after radical cystectomy for urothelial bladder tumour. MATERIALS AND METHOD: 120 patients were treated for pure urothelial bladder tumour with pelvic lymphadenectomy, between January 1980 and January 1999, in a single centre. The prognostic value of the various sub-sites was studied by univariate and multivariate survival analysis. RESULTS: The 5-year survival decreased from 62% to 19% in the case of a lesion involving the bladder dome (p = 0.0001). Multivariate analysis demonstrated the following independent prognostic factors: local invasion pT < or = 3 (p = 0.003), lymph node involvement (p = 0.05) and involvement of the dome (p = 0.002). Other tumour sub-sites had an effect on survival on univariate analysis that was not confirmed on multivariate analysis. CONCLUSION: Although stages pT and pN are prognostic factors recognized by all studies, invasion of the bladder dome appears to have a major independent influence on survival. This result must be confirmed by other studies, in view of its potential influence for determination of homogeneous patient groups in controlled trials.

Adult↗

PubMed2005

The effect of tumor location and respiratory function on tumor movement estimated by real-time tracking radiotherapy (RTRT) system.

PURPOSE: The effects of tumor location and pulmonary function on the motion of fiducial markers near lung tumors were evaluated to deduce simple guidelines for determining the internal margin in radiotherapy without fiducial markers. METHODS AND MATERIALS: Pooled data collected by a real-time tumor-tracking radiotherapy system on 42 markers in 39 patients were analyzed. The pulmonary functions of all patients were assessed before radiotherapy. Using chest X-ray film, the position of the marker was expressed relative to the geometry of the unilateral lung. Posterior location meant the area of the posterior half of the lung in a lateral chest X-ray film, and caudal location meant the caudal half of the chest X-ray film; these categories were determined by measuring the distance between the marker and anatomic landmarks, including the apex, costophrenic angle, midline of spinal canal, lateral, anterior, and posterior boundary of the lung. RESULTS: Before the radiotherapy, 18 patients had obstructive respiratory dysfunction (ratio of forced expiratory volume in 1 s to forced vital capacity [FEV1.0/FVC] <70), 5 patients had constrictive dysfunction (percent vital capacity [%VC] <80), and 3 had mixed dysfunction. Means of FEV1.0/FVC and %VC were 97.0% and 66.5%, respectively. Median tumor movements in the x (left-right), y (anteroposterior), and z (craniocaudal) directions were 1.1 mm, 2.3 mm, and 5.4 mm, respectively. There was no significant correlation between respiratory function and magnitude of marker movement in any direction. Median marker movement in the z direction was 2.6 mm for the cranial location and 11.8 mm for the caudal location, respectively (p < 0.001). Median movement in the z direction was 11.8 mm for posterior location and 3.4 mm for anterior location, respectively (p < 0.01). CONCLUSIONS: Simple measurement of the relative location on plain chest X-ray film was related, but respiratory function test was not related, to the craniocaudal amplitude of the motion of the fiducial marker near lung tumors.

Adult↗

PubMed2004

Dynamic first pass 3D EPI of the prostate: accuracy in tumor location.

PURPOSE: To evaluate the potential of dynamic contrast enhanced (DCE) 3D EPI in the location of prostate cancer. MATERIAL AND METHODS: A DCE 3D EPI scan was included in the magnetic resonance imaging protocol for prostate examination. Twenty-eight patients who subsequently underwent radical prostatectomy were included in the study. T2-weighted (T2W) Turbo Spin Echo (TSE) images were initially evaluated by two radiologists. Parametric images reflecting contrast enhancement were added and new evaluations performed. The results were compared with histology from resected specimens. Accuracies and interobserver agreements were calculated. RESULTS: Interobserver agreement was Kw =49+/-3% for the T2W technique and Kw=30+/-3% for the combined techniques. No statistically significant advantages were found for location of tumor in the prostate or in the seminal vesicles by adding the DCE information. CONCLUSION: DCE 3D EPI did not improve tumor location compared with that of T2W TSE images. Further investigation is needed on how best to exploit the DCE technique.

Aged↗

PubMed1999

Cavernous sinus sampling is highly accurate in distinguishing Cushing's disease from the ectopic adrenocorticotropin syndrome and in predicting intrapituitary tumor location.

Inferior petrosal sinus sampling (IPSS) is used to distinguish pituitary Cushing's disease from occult cases of the ectopic ACTH syndrome, but is limited in that it requires the use of ovine CRH (oCRH) and is not highly accurate at predicting the intrapituitary location of tumors. This study was designed to determine whether cavernous sinus sampling (CSS) is as safe and accurate as IPSS, whether CSS can eliminate the need for oCRH stimulation, and whether CSS can accurately predict the intrapituitary location of tumors. Ninety-three consecutive patients with ACTH-dependent Cushing's syndrome were prospectively studied with bilateral, simultaneous CSS before and after oCRH stimulation. Prediction of a pituitary or ectopic ACTH source was based on cavernous/peripheral plasma ACTH ratios. Intrapituitary tumor location was predicted based on lateralization (side to side) ACTH ratios. These predictions were compared to surgical outcome in the 70 patients who had surgically proven pituitary (n = 65) or ectopic (n = 5) disease. CSS distinguished pituitary Cushing's disease from the ectopic ACTH syndrome in 93% of patients with proven tumors before oCRH administration and in 100% of patients with proven tumors after oCRH. It was as safe and efficacious as published IPSS results. CSS accurately predicted the intrapituitary lateralization of the tumor in 83% of all patients and 89% of those patients with good catheter position and symmetric venous flow. CSS is as safe and accurate as IPSS for distinguishing patients with pituitary Cushing's disease from those with the ectopic ACTH syndrome. In addition, CSS appears to be superior to IPSS for predicting intrapituitary tumor lateralization.

ACTH Syndrome, Ectopic↗

PubMed1994

Influence of extent of surgery and tumor location on treatment outcome of patients with glioblastoma multiforme treated with combined modality approach.

Between 1988 and 1991, eighty-six patients with glioblastoma multiforme were evaluated in order to define the influence of extent of surgery and tumor location on treatment outcome. Patients underwent surgery followed by postoperative hyperfractionated radiotherapy and chemotherapy delivered according to one of two consecutive protocols. Surgery consisted of biopsy in 25 (29%) patients and subtotal or gross total tumor resection in 61 (71%) patients. Frontally located tumors were noted in 26 (30%) patients and other tumor locations were noted in 60 (70%) patients. Patients having more radical surgery had longer median survival time (MST) and higher 1- and 2-year survival rates than those with biopsy only (56 vs 29 weeks, respectively; 62% and 23% vs 16% and 0%, respectively; p = 0.00000). Patients having frontally located tumors had longer MST and higher 1- and 2-year survival rates than those with other tumor locations (101 vs 47 weeks, respectively; 76% and 44% vs 37% and 2.5%, respectively; p = 0.00001). Multivariate analysis confirmed that extent of surgery and tumor location were independent prognostic factors in patients with glioblastoma multiforme. Regarding progression-free survival, patients having more radical surgery had longer median time to tumor progression (MTP) than those with biopsy only (33 weeks vs 21 weeks, respectively). Also, progression-free survival at 1 year was higher in radically resected group than in biopsy only group (20% vs 0%, respectively; p = 0.00000). Patients with frontally located tumors had longer MTP (42 weeks) and higher progression-free survival at 1 year (42%) than those with other tumor location (28 weeks and 1.7%, respectively; p = 0.00002).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2000

[Microsurgical treatment of medially located tumors of the middle skull base].

OBJECTIVE: To report the results of microsurgical treatment of tumors medially located in the middle skull base. METHODS: The preoperative MRI features, operative approaches, results of operation and postoperative complications in 26 cases were reviewed. RESULTS: Total resection of the tumors was achieved in 12 cases, subtotal resection in 9 cases, partial resection in 6 cases. Two patients died of operation. Cranial nerve palsy remained unchanged in 5 cases and became exacerbated in 5 cases. Clinical improvement was observed in 15 cases. CONCLUSION: The combined frontotemporal-zygomatic approach to remove medially located tumors of the middle skull base is adequate.

Adolescent↗

PubMed1998

Racial differences and prognostic significance of tumor location in radical prostatectomy specimens.

BACKGROUND: Our objective was to evaluate radical prostatectomy specimens for possible racial differences in tumor location, as well as to correlate tumor location with pathologic stage and disease-free survival. METHODS: Between January 1991-December 1997, 1,245 patients underwent radical prostatectomy with bilateral pelvic lymphadenectomy for clinically localized prostate cancer. Seven hundred and eighty-five patients who were treated with surgery as monotherapy were evaluated. Tumor location, defined as mainly anterior, mainly posterior, or both (anterior and posterior), was obtained from review of tumor maps prepared from pathological evaluation of completely embedded, resected specimens. RESULTS: Overall tumor location was anterior in 107 (14%), posterior in 459 (58%), and both in 219 (28%) cases. The incidence of anterior tumors was higher in African American men compared to Caucasians (16% vs. 11%, P = 0.045). The rate of positive surgical margins in anteriorly and posteriorly located tumors was 60% vs. 38% in African American men (P = 0.001) and 48% vs. 27% in Caucasians (P = 0.001), respectively. African American men were found to have a higher incidence of positive surgical margins (50%; 174/348) compared to Caucasian men (34%; 150/437; P = 0.001). CONCLUSIONS: Anterior tumors were present in 14% of our patients. African American men have a greater percentage of anterior tumors than do Caucasians. In addition, a higher rate of positive surgical margins was encountered in patients with anterior tumors, especially if they were African American men. In patients with an abnormal serum prostate-specific antigen level and negative sextant prostate biopsies, we recommend biopsy of the anterior zone of the prostate.

Adult↗

PubMed1983

The prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Findings from the NSABP clinical trials.

The present study examines the prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Data were obtained from 1021 patients entered into two randomized prospective clinical trials of the NSABP. Tumor location proved to be a strong prognostic discriminant. Lesions located in the left colon demonstrated the most favorable prognosis. Tumors of the rectosigmoid and rectum had the worst prognosis with the relative risk of treatment failure for the latter being over three fold that of the left colon. When the relative risks associated with tumor location were adjusted for nodal imbalances, the left colon continued to demonstrate the most favorable prognosis. The presence of bowel obstruction also strongly influenced the prognostic outcome. Examination of the data without considering tumor location disclosed that patients with bowel obstruction were at greater risk for treatment failure than those without obstruction. The effect of bowel obstruction was influenced by the location of the tumor. The occurrence of bowel obstruction in the right colon was associated with a significantly diminished disease-free survival, whereas obstruction in the left colon demonstrated no such effect. This phenomenon was independent of nodal status and tumor encirclement, the latter two factors proving to be of prognostic significance independent of tumor obstruction. A multivariate analysis in which the covariate effects of sex, age, nodal status, tumor obstruction, encirclement, and tumor location were adjusted underscored the role of tumor location and obstruction as prognostic discriminants. The results indicate that the definition of prognostic factors can identify patient subsets with unique characteristics.

Carcinoma↗

PubMed2006

Orbital decompression as an alternative management strategy for patients with benign tumors located at the orbital apex.

PURPOSE: Tumors located in the intraconal portion of the orbital apex, especially those inferior to the optic nerve, can be difficult to access surgically, carrying a significant risk of ocular morbidity. The purpose of this study was to investigate outcomes in 5 patients with benign-appearing but symptomatic tumors located in the intraconal portion of the orbital apex in which orbital decompression was performed as an alternative management strategy to resection. DESIGN: Retrospective interventional case series. PARTICIPANTS: Five patients were diagnosed with a compressive optic neuropathy secondary to a benign-appearing tumor at the orbital apex. INTERVENTION: Each patient underwent surgical decompression of the affected orbit. None of the patients had the tumor biopsied or resected. MAIN OUTCOME MEASURES: Best-corrected visual acuity (VA), pupillary responses, visual fields (VFs), color vision, and orbital imaging. RESULTS: Each of the patients demonstrated improvement in visual function, as measured by VA, VFs, and, in some cases, color vision. One patient required a second orbital decompression for recurrent optic neuropathy 4 years after the initial decompression. Complications included ptosis and enophthalmos in 2 patients and diplopia in the extreme right gaze in 1 patient. CONCLUSIONS: Orbital decompression is a therapeutic option for patients with compressive optic neuropathies from benign orbital apex tumors, offering potential improvement in optic nerve function while sparing morbidity from attempts at surgical resection.

Adult↗

PubMed2000

Study of lymphatic metastatic patterns in gastric carcinoma according to tumor location.

A total of 226 cases of advanced gastric cancer which occupied only one third of the stomach were analyzed in order to clarify whether and how lymphatic spread differed according to the tumor location and gross type of tumor. Out of the 226 patients, 45 cases had tumor in the upper third, 74 cases had it in the middle third, and 107 cases had it in the lower third of the stomach. The incidence of lymph node metastasis was found to be much higher for the tumors located in the lesser curvature (51.6%), greater curvature and posterior wall (54.4%), as compared to the tumors located in the anterior wall (28.0%). The tumors located in the upper third of the stomach did not show any metastasis in the N3 node, while the tumors located in the lower third of the stomach did not show any metastasis in the left cardial nodes, short gastric nodes, and the nodes along the left gastroepiploic vessels. Similarly, the tumors from the middle third of the stomach did not invade the left cardial nodes.

Adult↗

PubMed2001

Reliable lymphatic drainage to axillary sentinel lymph nodes regardless of tumor location within the breast.

BACKGROUND: This analysis was performed in order to determine whether primary tumor location in breast cancer affects the axillary sentinel lymph node (SLN) identification (ID) rate, the false negative (FN) rate, incidence of axillary nodal metastases, or the number of SLN identified. METHODS: In this prospective multi-institutional study, SLN biopsy was performed on clinical stage T1-2, N0 breast cancer patients using blue dye alone or in combination with radioactive colloid, followed by completion axillary LN dissection. RESULTS: Central tumor location was associated with an improved FN rate, which may be related to reliable drainage from the subareolar lymphatic plexus. Tumor location did not significantly affect the SLN ID rate or the mean number of SLN identified. Medial tumor location was associated with a decreased rate of axillary nodal metastasis. CONCLUSIONS: Breast cancers drain reliably to the axillary lymph nodes regardless of tumor location within the breast.

Axilla↗

PubMed1995

[A study of tumor location and prognosis in renal pelvic and ureteral cancer].

A total of 245 patients with renal pelvic and ureteral cancer (transitional cell carcinoma) were retrospectively analysed for tumor location and prognosis. In 133 renal pelvic cancer patients, 34 patients (25.6%) had tumor in lower calyx, 33 patients (24.8%) in renal pelvis, 31 patient (23.3%) in upper calyx, 21 patients (15.8%) in whole renal pelvis and 7 patients (5.2%) in middle calyx, respectively. In 128 ureteral cancer patients, 60 patients (46.9%) had tumor in lower ureter, 27 patients (21.1%) in distal end of ureter, 26 patients (20.3%) in middle ureter, 12 patients (9.4%) in upper ureter and 3 patients (2.3%) in whole ureter. In combination of tumor location, 101 patients (41.2%) had tumor in only renal pelvis, 94 patients (38.4%) had in only ureter, 14 patients (5.7%) had in renal pelvis and ureter, 19 patients (7.8%) had in renal pelvis and bladder, 12 patients (4.9%) had in ureter and bladder, and 5 patients (2%) had in renal pelvis, ureter and bladder. Five year survival rate of renal pelvic cancer according to tumor location were 55.9% in upper calyx tumor, 60.8% in middle calyx tumor, 63.8% in lower calyx tumor, 60.2% in renal pelvic tumor and 63.8% in PUJ tumor, respectively. There were no significant difference between those 5 groups. Five years survival rate of ureteral cancer according to tumor location, 90% in upper ureteral tumor, 60.8% in middle ureteral tumor, 66.5% in lower ureteral tumor and 52.6% in tumor of distal end of ureter, respectively. Also in those 4 groups, there were no significant difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2003

Tumor location cannot predict the mobility of lung tumors: a 3D analysis of data generated from multiple CT scans.

PURPOSE: There is limited information available on the three-dimensional (3D) motion of lung tumors. Data derived from multiple planning computed tomographic (CT) scans were used to characterize the 3D movement of small peripheral lung tumors. METHODS AND MATERIALS: A total of 29 data sets from patients with Stage I non-small-cell lung cancer (NSCLC), each of which consisted of three "rapid" and three "slow" planning CT scans, were analyzed. All six scans were coregistered, and contoured gross tumor volumes (GTVs) were expanded by 5 mm to derive clinical target volumes (CTVs). Two-dimensional and 3D displacement vectors of the individual CTVs, relative to an "optimal" CTV derived from all six scans, were generated. Tumor mobility was correlated with location. Three-dimensional margins, which had to be added to individual CTVs to ensure coverage of "optimal" CTVs, were determined. RESULTS: No significant correlation was observed between the anatomic location of tumors and the extent of mobility in the x, y, and z axes. However, supradiaphragmatic lesions exhibited more mobility, particularly in the craniocaudal direction. The addition of a 3D margin of 5 mm to a single slow CTV ensured full coverage of the "optimal CTV". CONCLUSIONS: Lung tumors demonstrate significant mobility in all directions, and this did not closely correlate with anatomic location. Individualized assessment of tumor mobility remains necessary, and is possible when the CTV derived from a single slow scan is used for radiotherapy planning.

Carcinoma, Non-Small-Cell Lung↗

PubMed1994

Early-stage glottic carcinomas: effect of tumor location and full-length involvement on local tumor recurrence after radiation therapy.

PURPOSE: To correlate tumor location along the vocal cord with local control in stage I and II glottic carcinoma. MATERIALS AND METHODS: Sixty-five patients with stage I and 18 patients with stage II glottic cancer were irradiated with 4-MV x rays. Most patients received a total of 64-66 Gy, at a dose of 1.8-2.0 Gy/d. RESULTS: In stage I tumors, local-control probability was 96% +/- 2 (standard deviation); in stage II tumors, 67% +/- 15. When stages I and II were considered together, tumors that involved the full length of the vocal cord were more likely to recur (P = .069). In stage I tumors, treatment with < 2.0 Gy/d was statistically significantly (P = .038) associated with local recurrence. CONCLUSION: Poor outcome after irradiation could not be predicted with involvement of either the anterior commissure or posterior third of the vocal cord. Risk of tumor recurrence increased with full-length involvement, and in stage I tumors, with a daily fraction < 2.0 Gy.

Glottis↗

PubMed2006

Tumor location of the lower-inner quadrant is associated with an impaired survival for women with early-stage breast cancer.

BACKGROUND: There is growing evidence that tumors of the inner quadrants (especially the lower-inner quadrant) metastasize more often to the internal mammary chain (IMC). As these metastases are not investigated, patients with lower-inner quadrant tumors have an increased risk of being under-staged and under-treated and may therefore have a higher risk of death from breast cancer. METHODS: We identified all 1522 women operated for stage I breast cancer between 1984 and 2002 recorded at the population-based Geneva Cancer Registry. We compared breast cancer mortality risk by tumor location with multivariate Cox regression analysis that accounted for all factors linked to tumor location and survival. RESULTS: Ten-year disease-specific survival was 93% (95%CI: 91-94%). Patients with breast cancer of the lower-inner quadrant (n = 118; 7.8%) had an importantly increased risk of dying of breast cancer compared to women with breast cancer of the upper-outer quadrant (multiadjusted Hazard Ratio: 2.3, 95%CI: 1.1-4.5, P = 0.0206). The over-mortality associated with this quadrant was particularly evident for tumors >10 mm (multiadjusted HR: 3.6, 95%CI: 1.6-7.9, P = 0.0016). There was no increased breast cancer mortality risk for tumors located in other quadrants. CONCLUSIONS: Tumor location in the lower-inner quadrant is an independent and important prognostic factor of stage I breast cancer. Further research is needed to evaluate if the over-mortality of patients with stage I cancer of the lower-inner quadrant is indeed a result of under-treatment due to undetected IMC metastases. If so, patients with stage I breast cancer of the lower-inner quadrant are good candidates for systematic IMC investigation.

Adenocarcinoma, Mucinous↗

PubMed2001

Laparoscopic intragastric stapled resection of gastric submucosal tumors located near the esophagogastric junction.

BACKGROUND: Laparoscopic resection cannot be applied easily to tumors located near the esophagogastric junction or the pyloric ring. We evaluated our laparoscopic intragastric surgical technique for gastric submucosal tumors located near the esophagogastric junction and the results of a clinical study. MATERIALS AND METHODS: We performed our technique in six patients: one man and five woman with a mean age of 61 years. Using the laparoscopic procedure, after inflation of the stomach, we inserted two or three balloon-type ports into the stomach through the abdominal wall. RESULTS: A stapled resection of gastric submucosal tumors using a laparoscopic linear stapler was performed successfully in all the patients. Without exception, stapled resections were successfully performed. The mean operation time was 168 min, and the blood loss was minimal There were no intra- or postoperative complications. The mean postoperative hospital stay was 9.8 days. The mean maximal diameter size of the resected specimens was 2.4 cm. Histopathologic diagnoses were gastrointestinal stromal tumors in five cases and enterogenous cyst in one. There were no recurrences during a mean follow-up period of 27 +/- 11.6 months. CONCLUSION: Although we need to evaluate the long-term outcomes, our procedure is considered technically feasible, safe, and useful for the resection of gastric submucosal tumors located near the esophagogastric junction.

Adult↗

PubMed2001

Dukes B colorectal cancer: distinct genetic categories and clinical outcome based on proximal or distal tumor location.

PURPOSE: The aim of this study was to determine whether tumor location proximal or distal to the splenic flexure is associated with distinct molecular patterns and can predict clinical outcome in a homogeneous group of patients with Dukes B (T3-T4, N0, M0) colorectal cancer. It has been hypothesized that proximal and distal colorectal cancer may arise through different pathogenetic mechanisms. Although p53 and Ki-ras gene mutations occur frequently in distal tumors, another form of genomic instability associated with defective DNA mismatch repair has been predominantly identified in the proximal colon. To date, however, the clinical usefulness of these molecular characteristics remains unproven. METHODS: A total of 126 patients with a lymph node-negative sporadic colon or rectum adenocarcinoma were prospectively assessed with the endpoint of death by cancer. No patient received either radiotherapy or chemotherapy. p53 protein was studied by immunohistochemistry using DO-7 monoclonal antibody, and p53 and Ki-ras gene mutations were detected by single strand conformation polymorphism assay. RESULTS: During a mean follow-up of 67 months, the overall five-year survival was 70 percent. Nuclear p53 staining was found in 57 tumors (47 percent), and was more frequent in distal than in proximal tumors (55 vs. 21 percent; chi-squared test, P < 0.001). For the whole group, p53 protein expression correlated with poor survival in univariate and multivariate analysis (log-rank test, P = 0.01; hazard ratio = 2.16; 95 percent confidence interval = 1.12-4.11, P = 0.02). Distal colon tumors and rectal tumors exhibited similar molecular patterns and showed no difference in clinical outcome. In comparison with distal colorectal cancer, proximal tumors were found to be statistically significantly different on the following factors: mucinous content (P = 0.008), degree of histologic differentiation (P = 0.012), p53 protein expression, and gene mutation (P = 0.001 and 0.01 respectively). Finally, patients with proximal tumors had a marginally better survival than those with distal colon or rectal cancers (log-rank test, P = 0.045). CONCLUSION: In this series of Dukes B colorectal cancers, p53 protein expression was an independent factor for survival, which also correlated with tumor location. Eighty-six percent of p53-positive tumors were located in the distal colon and rectum. Distal colon and rectum tumors had similar molecular and clinical characteristics. In contrast, proximal neoplasms seem to represent a distinct entity, with specific histopathologic characteristics, molecular patterns, and clinical outcome. Location of the neoplasm in reference to the splenic flexure should be considered before group stratification in future trials of adjuvant chemotherapy in patients with Dukes B tumors.

Adenocarcinoma↗