Endocrine therapy with or without whole breast irradiation in low-risk breast cancer patients after breast-conserving surgery: 10-year results of the Austrian Breast and Colorectal Cancer Study Group 8A trial.

PURPOSE: To investigate long-term results of patients with hormonal receptor-positive breast cancer treated with breast-conserving surgery (BCS) and consecutive endocrine therapy (ET) with or without whole breast irradiation (WBI). METHODS AND MATERIALS: Within the 8 A trial of the Austrian Breast and Colorectal Cancer Study Group, a total of 869 patients received ET after BCS which was randomly followed by WBI (n = 439, group 1) or observation (n = 430, group 2). WBI was applied up to a mean total dosage of 50 Gy (+/- 10 Gy boost) in conventional fractionation. RESULTS: After a median follow-up of 9.89 years, 10 in-breast recurrences (IBRs) were observed in group 1 and 31 in group 2, resulting in a 10-year local recurrence-free survival (LRFS) of 97.5% and 92.4%, respectively (p = 0.004). This translated into significantly higher rates for disease-free survival (DFS): 94.5% group 1 vs 88.4% group 2, p = 0.0156. For distant metastases-free survival (DMFS) and overall survival (OS), respective 10-year rates amounted 96.7% and 86.6% for group 1 versus 96.4% and 87.6%, for group 2 (ns). WBI (hazard ratio [HR]: 0.27, p < 0.01) and tumour grading (HR: 3.76, p = 0.03) were found as significant predictors for IBR in multiple cox regression analysis. CONCLUSIONS: After a median follow-up of 10 years, WBI resulted in a better local control and DFS compared with ET alone. The omission of WBI and tumour grading, respectively, were the only negative predictors for LRFS.

• Pancho trial (p53-adapted neoadjuvant chemotherapy for resectable esophageal cancer) completed-mutation rate of the marker higher than expected.

BACKGROUND: In operable esophageal cancer patients, neoadjuvant therapy benefits only those who respond to the treatment. The • Pancho trial represents the first prospective randomized trial evaluating the relevance of the mark53 status for predicting the effect of two different neoadjuvant chemotherapies. METHOD: Biomarker analysis was conducted using the mark53 analysis. Calculation of patient number needed was based on a 60% rate of marker positivity, deduced from the results of a phase II pilot study. RESULTS: From 2007-2012, the • Pancho trial recruited 235 patients with operable esophageal cancer in Austria. A total of 181 patients were eligible and could be subjected to mark53 analysis and randomization. After randomizing 74 patients, the overall TP53 mutation rate was 79%. However, due to the high prevalence of marker positivity, the number of projected patients was increased to 181 patients in order to ensure a sufficient number of marker-negative patients. After completion of the trial, the overall TP53 mutation rate was 77.9%. CONCLUSION: Due to high medical need, the recruitment for the academic trial was excellent. Mark53 analysis clearly detected more mutations in the TP53 gene as compared to the cancer-specific p53 literature. Final analysis examining the interaction between the mark53 status and the effect of chemotherapies applied in the • Pancho trial is now awaited.

The biomarker TP53 divides patients with neoadjuvantly treated esophageal cancer into 2 subgroups with markedly different outcomes. A p53 Research Group study.

BACKGROUND: Fluorouracil and cisplatin have been used most frequently as neoadjuvant therapy for esophageal cancer. Both drugs are believed to act via a p53-dependent apoptosis pathway. The TP53 gene is frequently mutated in esophageal cancer. OBJECTIVE: To test the value of TP53 as a biomarker prognosing outcome in patients with neoadjuvantly treated esophageal cancer. PATIENTS AND METHODS: The investigation included 36 patients with primary operable esophageal cancer who were treated neoadjuvantly with cisplatin and fluorouracil. The TP53 genotype was assessed from paraffin-embedded diagnostic tumor biopsies using a standardized gene-specific TP53 sequencing protocol (mark53 kit; mark53 Ltd, Vienna, Austria). RESULTS: Mutations in the TP53 gene were present in 50% of tumors. Two-year overall survival rates were 55.6% in patients with a normal TP53 marker status, compared with 16.7% in those with a mutant TP53 gene. In patients with normal TP53, neoadjuvant treatment resulted in significant advantages in terms of tumor-associated survival (P=.0049) and overall survival (P=.0304) compared with those with mutant TP53. The median tumor-associated survival was 34.2 months for patients with normal TP53, compared with 8.9 months for those with mutant TP53. The latter had a 3-fold higher risk of dying (hazard ratio, 3.01; 95% confidence interval, 1.359-6.86). CONCLUSIONS: The biomarker TP53 divides esophageal cancer patients into 2 categories with markedly different outcomes: patients with a normal TP53 marker status may experience notable benefits from neoadjuvant chemotherapy with cisplatin/fluorouracil, whereas those with a mutant TP53 marker status appear to be at risk for lack of response.

Growing clinical evidence for the interaction of the p53 genotype and response to induction chemotherapy in advanced non-small cell lung cancer.

OBJECTIVE: The objective of this study is to establish clinical evidence that the p53 genotype can serve as a predictive marker for response to cisplatin-based induction therapy. METHODS: Patients with advanced non-small cell lung cancer who had received neoadjuvant chemotherapy in the context of a prospective phase II trial were analyzed for the p53 genotype of their tumors. Response to induction therapy was then correlated to the p53 genotype as assessed by complete direct DNA sequencing. Patients had received 3 cycles of cisplatin and etoposide, and 1 cycle of simultaneous radiochemotherapy. All 3 treatment components mediate their cytotoxic effect through induction of apoptosis, which is suggested to require an intact p53 gene. In addition, the results from a previously published hypothesis-finding study are updated to demonstrate the consistency of clinical results and summarize currently available clinical evidence. RESULTS: In the phase II trial, 35 patients underwent resection after induction chemotherapy, allowing a pathohistologic response assessment. The presence of a mutant p53 genotype was highly indicative of resistance to induction chemotherapy (P < .002). The sensitivity of a mutant p53 genotype to identify nonresponders was 94% (71.3-99.9 confidence interval). A normal p53 gene was significantly associated with radical resection (P < .004) and survival advantage (P = .02). CONCLUSION: This is the second clinical evaluation demonstrating a significant relation between p53 genotype and response to induction therapy in non-small cell lung cancer. We conclude that the p53 genotype should be evaluated as a predictive marker for response to induction therapy in prospective randomized protocols.

TP53 genotype but not p53 immunohistochemical result predicts response to preoperative short-term radiotherapy in rectal cancer.

OBJECTIVE: To evaluate and compare the predictive power of p53 gene analysis versus p53 immunohistochemical staining in terms of response to preoperative short-term radiotherapy using 25 Gy in operable rectal cancer. SUMMARY BACKGROUND DATA: Recent studies show that p53 may be a determinant of radiosensitivity being required for induction of apoptosis in case of radiation-induced DNA damage. METHODS: Preirradiation biopsy samples of 64 patients with rectal carcinoma were analyzed. Genetic alterations of the p53 gene were detected by complete direct sequencing of exons 2 to 10. Expression of the nuclear phosphoprotein p53 was assessed by immunohistochemical staining. Results were correlated with histopathology of resected specimens and follow-up data, respectively. RESULTS: Mutations of the p53 gene were present in 45% of tumors. Patients with a normal p53 gene had a significant survival advantage. Comparing pre- and postradiotherapy T category, a reduction was seen in patients with normal p53 genotype only. A mutant p53 genotype was highly specific in indicating stable disease concerning T category after irradiation. Protein overexpression was detected in 61%. Overexpression of the p53 protein was not related to survival or response. The concordance between immunohistochemistry and sequencing was only 0.51. CONCLUSIONS: The authors show that downstaging after short-term radiation may occur but is seen in tumors with normal p53 gene only. Moreover, p53 genotype but not p53 immunohistochemistry is predictive for response to preoperative short-term radiotherapy and patient survival.