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Biomedical subjects

M Pilepich

Publications and source records attributed to M Pilepich.

7 recordsLinked to original sources

Loss of p16 expression is of prognostic significance in locally advanced prostate cancer: an analysis from the Radiation Therapy Oncology Group protocol 86-10.

PURPOSE: The retinoblastoma (RB) cell cycle regulatory pathway is known to be deregulated in virtually all known human tumors. The protein product of the RB gene, pRB, and its upstream regulator, p16, are among the most commonly affected members of this pathway. We investigated the prognostic significance of both pRB and p16 expression in locally advanced prostate cancers, from patients treated on the Radiation Therapy Oncology Group (RTOG) protocol 86-10. MATERIALS AND METHODS: Sixty-seven cases from RTOG 86-10 had immunohistochemically stained slides, judged interpretable for both p16 and pRB, available for analysis. Median follow-up was 8.9 years (range, 6.0 to 11.8 years) for surviving patients. Staining for each marker was then correlated with overall survival, local progression, distant metastasis, and disease-specific survival. RESULTS: Loss of p16 expression, as defined by expression was significantly associated with reduced overall survival (P =.039), disease-specific survival (P =.006), and higher risk of local progression (P =.0007) and distant metastasis (P =.026) in the univariate analysis. In the multivariate analysis, loss of p16 was significantly associated with reduced disease-specific survival (P =.0078) and increased risk of local failure (P =.0035) and distant metastasis (P =.026). A borderline association with reduced overall survival (P =.07) was also evident. Loss of pRB was associated with improved disease-specific survival on univariate (P =.028) and multivariate analysis (P =.043), but carried no other significant outcome associations. CONCLUSION: Loss of p16 is significantly associated with adverse clinical outcome in cases of locally advanced prostate cancer.

Adult↗

Survival advantage from higher-dose radiation therapy for clinically localized prostate cancer treated on the Radiation Therapy Oncology Group trials.

PURPOSE: We evaluated the effect of external-beam radiation therapy on disease-specific survival (death from causes related to prostate cancer) and overall survival in men with clinically localized prostate cancer. METHODS: From 1975 to 1992, 1,465 men with clinically localized prostate cancer received radiation therapy on four Radiation Therapy Oncology Group phase III randomized trials and were pooled for this analysis. No one received androgen-deprivation therapy with his initial treatment. All original histology had central pathologic review for grading using the Gleason classification system. Total delivered radiation dose ranged from 60 to 78 Gy (median, 68.4 Gy). The median follow-up time was 8 years. RESULTS: A Cox regression model revealed that Gleason score was an independent predictor of disease-specific survival and overall survival. The 10-year disease-specific survival rates by Gleason score were as follows: score of 2 through 5, 85%; score of 6, 79%; score of 7, 62%; and score of 8 through 10, 43%. Stratifying outcome by this important prognostic factor revealed that higher radiation dose was a significant predictor for improved disease-specific survival and overall survival only for those patients whose cancers had Gleason scores of 8 through 10 (P <.05). After adjusting for clinical T stage, nodal status, and age, treating with a higher radiation dose was associated with a 29% lower relative risk of death from prostate cancer and 27% reduced mortality rate (P <.05). CONCLUSION: These data demonstrate that higher-dose radiation therapy can significantly reduce the risk of dying from prostate cancer in men with clinically localized disease. This survival benefit is restricted to men with poorly differentiated cancers.

Aged↗

Effect of preoperative irradiation on resectability of colorectal carcinomas.

From 1968 to January 1, 1977, 44 patients with initially unresectable colorectal carcinoma were treated with preoperative radiotherapy and surgery. On presentation, unresectability was determined either clinically (26 patients) or by preradiotherapy laparotomy (18 patients). Preoperative irradiation consisted of 4500-5000 rad. After radiotherapy, 33 of 44 lesions were considered resectable. Seven of 33 patients underwent incomplete resection with mean survival of 17 months. Resection was complete in 26 of the 33 patients. Of the latter group (26), 18 patients are alive with no evidence of disease with minimum follow-up of 36 months. Detailed results are discussed.

Adult↗

Multimodal therapy in metastatic Ewing's sarcoma: an Intergroup Study.

Multimodal therapy consisting of radiation therapy to all areas of gross disease and intensive combination chemotherapy was administered to 44 patients with Ewing's sarcoma. Seven of these patients had regional disease and the others had clinical evidence of distant metastases. The median duration of time on study for all patients was 75 weeks. A complete response occurred in 31 of the patients and 17 are currently free of disease. Four deaths resulted from complications of therapy; 2 were due to infection and 2 due to adriamycin-related cardiomyopathy.

Bone Neoplasms↗

Use of body scanner in radiotherapy treatment planning.

CT body scans obtained on 98 patients before, during, and after radiotherapy were evaluated for their utility in radiotherapy treatment planning and in follow-up after radiotherapy. Twenty-two patients were studied after irradiation. Four received additional treatment, and continuing or planned treatment was withheld from another four on the basis of CT data. Tumor extent was clearly delineated on CT scan in 48/76 cases (63%), suggestive in 25/76 (33%), and not seen in only three (4%). Utilizing CT data relative to all other available tests, in 75 patients, total treatment volume was altered in 34 (45%), tumor coverage was marginal or inadequate in 35 (47%), and volume of normal tissue irradiated was changed in 34 (45%). CT scan data was judged essential for treatment planning in 41, or 55%, of patients studied. Unsuspected areas of tumor involvement were seen in 32 of 75 cases (43%). Use of the CT scan as a patient contour for radiotherapy treatment planning and alternative techniques for inputting the CT data to treatment planning computers are discussed. A simple inexpensive device to accomplish this is described. Speculations are made regarding the impact of CT scanners on transverse axial tomography units and treatment simulators as well as the potential application of the technique in brachytherapy dose computation.

Abdominal Neoplasms↗