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OBJECTIVE: Neoadjuvant chemotherapy (NAC) in breast cancer (BC) is being considered for a broader range of cases, including locally advanced tumors and situations where downstaging could reduce extensive surgery. Several trials have explored predictive markers of pathological complete response (pCR). The role of Ki-67 as a predictor of pCR has been demonstrated in studies. However, the cut-off remains vague, given the lack of standardization of measurement methods. The aim of our study was to evaluate the predictive value of Ki-67 in response to NAC and to identify the cut-off values that exhibit the strongest correlation with best response. MATERIALS AND METHODS: This retrospective study included 187 patients who had undergone surgery following NAC for BC at the CHU Souss Massa of Agadir between January 2020 and January 2023. Logistic regression was used to assess the correlation between Ki-67 and patients' characteristics. Optimal Ki-67 cutoff was identified by receiver operating characteristic curve. Kaplan-Meier curves were used to assess disease-free survival (DFS), and survival comparisons were assessed with the log-rank test. RESULTS: The median age was 51.8±10.7 years and 51.4% of tumors were smaller than 5 cm. Node invasion was found in 55.4%. Luminal B subtype was found in 49.7%, followed by human epidermal growth factor receptor-2 (HER-2)-positive in 27.4%, triple-negative in 14.3% and Luminal A in 8.6%. pCR occurred in 40% of patients overall. Subgroup analysis revealed a significant association between pCR and tumor size (p<0.001), lymph node involvement (p<0.001), grade 2 (p<0.001), vascular invasion (p<0.001), and positive HER-2 status (p = 0.022). In statistical analysis, pathological responses were improved in patients with Ki-67 >35% (p<0.001). DFS was 98.8% at 12 months. No statistical difference was found in DFS according to Ki-67 values and pCR status. CONCLUSION: Our results indicate that Ki-67 is a predictive marker for response in the neoadjuvant setting in BC patients. Our study showed that a Ki-67 cut-off >35% predicts a better pCR rate in response to NAC. However, this cutoff value remains controversial due to the absence of a standard method of measurement, with inter- and intra-observer variability. It would be necessary to validate this cutoff in other studies.
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Background Colorectal cancer constitutes a significant public health challenge, despite remarkable strides made in the last two decades, particularly in the medical management of metastatic stages. Notable progress has been achieved through targeted therapies such as anti-epidermal growth factor receptors or anti-angiogenic antibodies, as well as advancements in surgical approaches for hepatic metastases. This study seeks to assess the efficacy and safety of bevacizumab plus chemotherapy in individuals with metastatic colorectal cancer. Methodology This is an observational, cross-sectional, retrospective study of all patients who were followed up for metastatic colorectal cancer with unresectable metastases and were treated with bevacizumab in combination with standard chemotherapy from January 2010 until December 2019 in the medical oncology department of the Centre Hospitalier Universitaire (CHU) Souss-Massa of Agadir. Results Of the total 162 cases, 117 (72%) had metastatic disease, and 45 (28%) progressed to metastatic disease after initial treatment. The median age of the patients was 55 years (range = 23-79 years) with a sex ratio of 1.1 (M/F). The tumor was located in the left colon in 135 (83.3%) patients. The results represented adenocarcinoma in 137 (84.6) cases and mucinous subtype in 23 (14.19) cases. The three most common sites of metastasis were the liver (99, 61.1), peritoneum (67, 41.3), and lung (33, 20.3). In the first line, all patients received bi-chemotherapy plus bevacizumab, i.e., fluorouracil, oxaliplatin, and leucovorin in 34 (20.9%) patients; capecitabine plus oxaliplatin in 88 (54.3%) patients; leucovorin, fluorouracil, and irinotecan in 17 (10.4%) patients; and capecitabine plus irinotecan in 23 (14.1%) patients. Response after first-line treatment was progression in 74 (45.7) cases, stability in 42 (25.9) cases, partial response in 35 (21.6) cases, and complete response in 11 (6.8) cases. Nine (6%) patients were able to benefit from surgical resection of metastatic lesions. Overall, 77 (47%) patients received second-line chemotherapy, i.e., 5-FU with irinotecan in 40 (51.8%) cases or with oxaliplatin in 30 (38.8%) cases. Two patients developed undesirable side effects under bevacizumab (hypertension). The median progression-free survival and median overall survival of the study cohort were 9 months and 14 months, respectively. Nevertheless, patients who underwent primary tumor resection (p = 0.048), those with rightsided tumors (p = 0.022), those who received a higher number of treatment cycles (p = 0.020), and those who received maintenance treatment (p = 0.001) had a longer median overall survival. Conclusions Chemotherapy combination with bevacizumab is considered as the cornerstone of metastatic colorectal cancer treatment in our region. With the new healthcare and social security systems, easier access to expensive treatments and molecular pathology tests is currently available. It is important to highlight that real-world data can offer valuable insights into the daily clinical practice of medical oncology.