Biomedical subjects

Alexandra L Hanlon

Publications and source records attributed to Alexandra L Hanlon.

44 records · Page 3Linked to original sources

PubMed2003

Modifying the American Society for Therapeutic Radiology and Oncology definition of biochemical failure to minimize the influence of backdating in patients with prostate cancer treated with 3-dimensional conformal radiation therapy alone.

PURPOSE: Adoption of the American Society for Therapeutic Radiology and Oncology (ASTRO) consensus definition has been critical for evaluating and comparing outcome following treatment with radiation. However, since its almost universal adoption, several points have remained controversial, notably backdating the date of failure to the point midway between the posttreatment prostate specific antigen (PSA) nadir and the first increase. We evaluated the impact of backdating on no biochemical evidence of disease (bNED) control and suggest changes in the definition. MATERIALS AND METHODS: Between April 1, 1989 and November 30, 1998, 1,017 patients with nonmetastatic prostate cancer were treated with 3-dimensional conformal radiation therapy alone. bNED control was defined using the ASTRO consensus definition. bNED failure was calculated from the time midway between the posttreatment PSA nadir and the first of the 3 consecutive increases in PSA (date of failure A). Four alternate failure time points were chosen, including backdating to the date of the first increase in PSA after the nadir, the date between the first and second consecutive PSA increases, the date between the second and third consecutive PSA increases, and the date of the third increase in PSA after the nadir (dates of failure 1 to 4). Kaplan-Meier estimates were calculated for all definitions of failure as well as hazard functions with time. Subset analyses based on prognostic group and followup time were also performed. RESULTS: The 10-year Kaplan-Meier bNED control rates were 64%, 52%, 47%, 42% and 39% using dates of failure A and 1 to 4, respectively. These differences persisted when patients were stratified by prognostic group. These same differences in bNED control were observed for the long-term followup subset, in which 10-year bNED control rates were 48%, 47%, 44%, 41% and 39% using dates of failure A and 1 to 4, respectively. CONCLUSIONS: Adoption of the ASTRO consensus definition has been crucial for evaluating outcome in the radiation oncology community. However, the date of failure should be moved from the current point to one closer to the point at which failure is declared. Additional analysis with large numbers of patients from multiple institutions is necessary to determine the point.

Adult↗

PubMed2003

Accuracy of determining nodal negativity in colorectal cancer on the basis of the number of nodes retrieved on resection.

BACKGROUND: Correct determination of nodal status is pivotal to accurate staging and predicting survival. METHODS: This is a secondary analysis of INT0089, an intergroup trial of adjuvant chemotherapy for high-risk stage II and III colon cancer. A subset of patients was studied who underwent right or left hemicolectomy and from whom at least 10 lymph nodes were examined. A mathematical model was created to estimate the probability of a true negative result on the basis of the number of nodes examined. The number of nodes needed to predict nodal negativity with 85%, 50%, and 25% probability on the basis of tumor stage was calculated. RESULTS: In this analysis, 1585 patients were studied. The average number of nodes removed at surgery was comparable between treatment groups at 18.5 (median of 16 in all groups). With this model, when 18 nodes are removed at resection, there is a <25% probability of true node negativity in T1/T2 tumors, whereas <10 nodes need to be examined in T3 and T4 tumors to achieve the same probability. CONCLUSIONS: Tumor stage and the number of nodes retrieved at resection influence the accuracy of determining nodal status in colon cancer. Most patients are understaged. Underestimating nodal stage may influence decisions regarding adjuvant therapy, as well as overall prognosis.

Adult↗

PubMed2002

Dose response in prostate cancer with 8-12 years' follow-up.

PURPOSE: This communication reports the long-term results of the original group of prostate cancer patients who participated in the first prospective Fox Chase Cancer Center radiation dose escalation study for which 8-12 years of follow-up is now available. METHODS AND MATERIALS: Between March 1, 1989 and October 31, 1992, 232 patients with clinically localized prostate cancer received three-dimensional conformal radiotherapy only at Fox Chase Cancer Center in a prospective dose-escalation study. Of these patients, 229 were assessable. The 8-, 10-, and 12-year actuarial rates of biochemical control (biochemically no evidence of disease [bNED]), freedom from distant metastasis (FDM), and morbidity were calculated. The Cox proportional hazards model was used to assess multivariately the predictors of bNED control and FDM, including pretreatment prostate-specific antigen (PSA) level (continuous), tumor stage (T1/T2a vs. T2b/T3), Gleason score (2-6 vs. 7-10), and radiation dose (continuous). The median total dose for all patients was 74 Gy (range 67-81). The median follow-up for living patients was 110 months (range 89-147). bNED control was defined using the American Society for Therapeutic Radiology and Oncology consensus definition. RESULTS: The actuarial bNED control for all patients included in this series was 55% at 5 years, 48% at 10 years, and 48% at 12 years. Patients with pretreatment PSA levels of 10-20 ng/mL had statistically significant differences (19% vs. 31% vs. 84%, p = 0.0003) in bNED control when stratified by dose (<71.5, 71.5-75.6, and > 75.6 Gy, respectively) on univariate analysis. For the 229 patients with follow-up, 124 (54%) were clinically and biochemically without evidence of disease. Sixty-nine patients were alive at the time of last follow-up, and 55 patients were dead of intercurrent disease. On multivariate analysis, radiation dose was a statistically significant predictor of bNED control for all patients and for unfavorable patients with a pretreatment PSA <10 ng/mL. For the patients with a pretreatment PSA level of 10-20 ng/mL, the radiation dose was a statistically significant predictor across all groups. No radiation dose response was seen for those patients with a pretreatment PSA level >20 ng/mL, although large numbers of patients are required to demonstrate a difference. The radiation dose, Gleason score, and palpation T stage were significant predictors for the entire patient set, as well as for those with pretreatment PSA levels between 10 and 20 ng/mL. The FDM rate for all patients included in this series was 89%, 83%, and 83% at 5, 10, and 12 years, respectively. For patients with pretreatment PSA levels <10 ng/mL, all four covariates (radiation dose, Gleason score, pretreatment PSA, and palpation T stage) were significant predictors of distance metastasis. Using the Radiation Therapy Oncology Group morbidity scale, no difference was noted in the frequency of Grade 2 and 3 genitourinary and Grade 3 gastrointestinal morbidity when patients in this data set were stratified by radiation dose. However, a significant increase occurred in Grade 2 gastrointestinal complications as the radiation dose increased. CONCLUSION: The long-term results of the original Fox Chase radiation dose escalation study with >9 years of median follow-up confirm the existence of a dose response for both bNED control and FDM. The dose response in prostate cancer is real, and the absence of biochemical recurrence after 8 years demonstrates the lack of late failure and suggests cure.

Actuarial Analysis↗

PubMed2002

Biochemical failure rates in prostate cancer patients predicted to have biologically insignificant tumors treated with three-dimensional conformal radiation therapy.

PURPOSE: It has been suggested that patients with prostate cancer meeting the following criteria have pathologically determined potentially biologically insignificant (PBI) tumor and therefore should be considered for observation: clinical stage T1c, PSA density <0.1 ng/mL per gram, absence of Gleason pattern 4 or 5, three or fewer biopsy cores positive for tumor, and tumor involvement of no more than 50% of any core. We compared the biochemical control rates in men meeting the above criteria to those of all low-risk patients (clinical T1c, PSA <or=15, Gleason score 2-6, no perineural invasion) to determine if these criteria reflect a low progression rate after definitive three-dimensional conformal radiation therapy. METHODS AND MATERIALS: Of 352 low-risk patients treated with three-dimensional conformal radiation therapy, 42 met the criteria describing potentially biologically insignificant tumor (PBI group). Median center of prostate dose for all patients was 74 Gy. Biochemical control was defined in accordance with the ASTRO consensus definition. RESULTS: Biochemical control rates at 5 and 7 years were 89% and 89% in the PBI group and 86% and 84% in the remaining low-risk patients, respectively (p = 0.62). CONCLUSIONS: In our experience, men meeting the criteria for potentially biologically insignificant tumor are not selected for a lower risk of biochemical failure and should not be specially selected for observation.

Aged↗

PubMed2002

Posttreatment prostate-specific antigen nadir highly predictive of distant failure and death from prostate cancer.

PURPOSE: To link posttreatment biochemical profiles to distant failure and cause-specific survival by assessing the relationship between posttreatment prostate-specific antigen (PSA) nadir and PSA doubling time (PSADT) with these outcome measures. METHODS AND MATERIALS: A total of 615 men were treated at the Fox Chase Cancer Center between April 1989 and December 1995 with three-dimensional conformal radiotherapy alone (median dose 73 Gy). The median follow-up was 64 months (range 2-135). Kaplan-Meier methods were used to estimate the rates of biochemical control, freedom from distant metastasis (FDM), and cause-specific survival. Multivariate predictors of outcome were assessed using stepwise Cox regression analysis. RESULTS: Multivariate analyses demonstrated that the predictors of improved biochemical control were a lower PSA nadir (p <0.0001), lower pretreatment PSA level (p <0.0001), Gleason score of 2-6 (p = 0.001), Stage T1-T2a tumors (p = 0.03), and higher RT dose (p = 0.02). The predictors of improved FDM were a lower PSA nadir (p <0.0001), longer interval to nadir from start of treatment (p = 0.0002), Gleason score of 2-6 (p = 0.005), androgen deprivation for biochemical failure (p = 0.001), and Stage T1-T2a tumors (p = 0.01). The predictors of improved cause-specific survival were a lower PSA nadir (p = 0.006) and longer interval to nadir from the start of treatment (p = 0.03). The 8-year FDM rate was 96%, 89%, and 61% for PSA nadir values of 2.0 ng/mL (p <0.0001), respectively. The 8-year cause-specific survival rate was 97%, 96%, and 78% for posttreatment PSA nadir values of 2.0 ng/mL (p <0.0001), respectively. For patients with sufficient PSA follow-up for PSADT calculations (n = 136), multivariate analysis of FDM from the time of biochemical failure demonstrated that androgen deprivation (p = 0.001), longer PSADT (p = 0.003), lower PSA nadir (p = 0.02), and longer interval to nadir from start of treatment (p = 0.04) were independent predictors of improved FDM. CONCLUSION: This is the first study, to our knowledge, to demonstrate the overwhelming predictive power of posttreatment PSA nadir for distant failure and death from prostate cancer. It is also the first study, to our knowledge, to demonstrate a strong association between posttreatment PSADT and distant failure. The results provide new information regarding disease progression as a function of posttreatment PSA profiles (time to achieve nadir from start of treatment, nadir, and PSADT) and the timing of androgen deprivation for biochemical relapse. This study may be used for the early identification of patients at high risk of distant metastasis and who may be directed to applicable systemic treatment clinical trials.

Aged↗

PubMed2002

Relationship between prostate volume, prostate-specific antigen nadir, and biochemical control.

PURPOSE: In patients treated with definitive three-dimensional conformal radiotherapy (3D-CRT) for localized prostatic adenocarcinoma, we sought to evaluate the relationship between pretreatment prostate gland volume and posttreatment prostate-specific antigen (PSA) nadir, as well as the relationship of prostate volume and PSA nadir with biochemical control (bNED). Two subgroups were studied: favorable (PSA <10 ng/mL, Gleason score 2-6, and T1-T2A) and unfavorable (one or more: PSA >/=10 ng/mL, Gleason score 7-10, T2B-T3). MATERIALS AND METHODS: A total of 655 men (n = 271 favorable and 384 unfavorable) were treated with 3D-CRT alone between May 1989 and November 1997. All patients had information on prostate volume and a minimum follow-up of 24 months (median 56, range 24-126). Of the 655 men, 481 (n = 230 favorable and 251 unfavorable) remained bNED at time of analysis, with biochemical failure defined in accordance with the American Society for Therapeutic Radiology and Oncology consensus definition. Factors analyzed for predictors of bNED included pretreatment prostate volume, posttreatment PSA nadir, pretreatment PSA, palpation T stage, Gleason score, center of the prostate dose, and perineural invasion (PNI). We also analyzed pretreatment prostate volume and its correlation to prognostic factors. For bNED patients, the relationship between PSA nadir and prostate volume was evaluated. RESULTS: On multivariate analysis, prostate volume (p = 0.04) and palpation T stage (p = 0.02) were the only predictors of biochemical failure in the favorable group. On multivariate analysis of the unfavorable group, pretreatment PSA (p <0.0001), Gleason score (p = 0.02), palpation T stage (p = 0.009), and radiation dose (p <0.0001) correlated with biochemical failure, and prostate volume and PNI did not. For all 481 bNED patients, a positive correlation between pretreatment volume and PSA nadir was demonstrated (p <0.0001). Subgroup analysis of the favorable and unfavorable patients also demonstrated a positive correlation between prostate volume and PSA nadir (p = 0.003 and p = 0.0002, respectively). Using multiple regression analysis, the following were found to be predictive of PSA nadir in all bNED patients: prostate volume (p <0.0001), pretreatment PSA (p <0.0001), palpation T stage (p = 0.0002), and radiation dose (p = 0.0034). Gleason score and PNI were not predictive. For the favorable group, palpation T stage (p = 0.0006), pretreatment PSA (p = 0.0083), prostate volume (p = 0.0186), and Gleason score (p = 0.0592) were predictive of PSA nadir, and PNI and radiation dose were not predictive. In the unfavorable group, prostate volume (p = 0.0024), radiation dose (p = 0.0039), pretreatment PSA (p = 0.0182), and palpation T stage (p = 0.0296) were predictive of PSA nadir, and Gleason score and PNI were not predictive. CONCLUSION: This report is the first demonstration that prostate volume is predictive of PSA nadir for patients who are bNED in both favorable and unfavorable subgroups. PSA nadir did not correlate with bNED status in the favorable patients, but it was strongly predictive in the unfavorable patients. Prostate gland volume was also predictive of bNED failure in the favorable but not the unfavorable group.

Aged↗

PubMed2002

Tumor above the spinal accessory nerve in papillary thyroid cancer that involves lateral neck nodes: a common occurrence.

OBJECTIVE: To describe the nature and extent of lateral neck node metastases from papillary thyroid cancer in relation to presenting physical examination and staging radiologic studies. DESIGN: Retrospective study. SETTING: Tertiary referral cancer center. PATIENTS: Consecutive patients who underwent comprehensive neck dissection with or without concurrent thyroidectomy for well-differentiated thyroid cancer between 1991 and 2001. Excluded were patients with well-differentiated thyroid cancer diagnosed incidentally at the time of treatment of other primary head and neck cancer, those with previous neck dissection for nonthyroid malignancies, and those undergoing surgery for medullary thyroid cancer. INTERVENTIONS: All pathology and operative and preoperative radiology reports for patients undergoing comprehensive neck dissection for well-differentiated thyroid malignancy were reviewed. Data were collected on previous procedures, preoperative evaluation, operative details, and pathologic findings. MAIN OUTCOME MEASURE: Identification of metastatic thyroid cancer in one or more nodes in anatomically defined drainage basins of the central and lateral neck. RESULTS: A total of 51 neck dissections were performed. All patients had preoperative evidence of metastatic disease. In addition to the usual comprehensive node dissection encompassing all lymphatic tissue in levels II through V, level I nodes and level II nodes above the spinal accessory nerve were labeled as distinct regions in 16 (31%) and 34 (67%) specimens, respectively. Disease was confined to a single nodal level in 20 (39%) of 51 specimens and was present in 4 or more levels in 7 (14%) of 50 neck dissections. There was cancer at 2 or 3 levels in 16 (31%) and 15 (29%) cases, respectively. Seven (21%) of the 34 patients undergoing separate analysis of nodes from above the spinal accessory nerve had cancer there. In 3 of the 34 it was the sole disease in level II. CONCLUSIONS: Tumor involvement at multiple nodal levels occurs in most cases when patients have lateral cervical node metastases. "Skip" metastases and cancer above the spinal accessory nerve are common. Neck dissections should include all node stations likely to be involved because selective node excision is likely to leave metastatic disease in situ.

Accessory Nerve↗

PubMed2002

Hypoxic prostate/muscle pO2 ratio predicts for biochemical failure in patients with prostate cancer: preliminary findings.

OBJECTIVES: To investigate whether low partial pressure of oxygen (PO2) in prostate cancer (CaP) predicts for biochemical outcome after radiotherapy. We previously reported that hypoxic regions exist in human CaP. METHODS: Custom-made Eppendorf PO2 microelectrodes were used to obtain approximately 100 PO2 readings from both pathologically involved regions of the prostate (as determined by sextant biopsies) and normal muscle (as an internal control). Fifty-seven patients with localized disease were prospectively studied; all received brachytherapy implants (48 low dose rate and 9 high dose rate) under spinal anesthesia. Nine patients had received prior hormonal therapy. Biochemical failure was defined as two consecutive rises in prostate-specific antigen level, without a return to baseline. Cox proportional hazards regression analysis was used to evaluate the influence of hypoxia on biochemical control, while adjusting for prostate-specific antigen, Gleason score, stage, implant type (low dose rate versus high dose rate), perineural invasion, hemoglobin level, use of hormonal therapy, average (mean) of the median prostate PO2, average median muscle PO2, and prostate/muscle PO2 (P/M) ratio. RESULTS: With a median follow-up of 19 months (range 4 to 31), 9 patients developed biochemical failure. A threshold analysis of the P/M ratio demonstrated that biochemical control at 2 years differed significantly at a ratio of less than 0.05 versus 0.05 or greater (31% versus 92%, P <0.0001). However, the classic prognosticators were similar in these two groups. On multivariate analysis, the P/M ratio was the only predictor of biochemical control (P = 0.0002). CONCLUSIONS: To our knowledge, this is the first study to correlate the degree of hypoxia in CaP with treatment outcome after radiotherapy. The P/M PO2 ratio was the strongest predictor for biochemical control on stepwise multivariate analysis. Longer follow up with more patients is planned to confirm this result.

Aged↗