Efficacy of Chemotherapy Rechallenge Versus Regorafenib or Trifluridine/Tipiracil in Third-Line Setting of Metastatic Colorectal Cancer: A Multicenter Retrospective Comparative Study.

PURPOSE: Metastatic colorectal cancer (mCRC) is a significant global health burden. This retrospective study compared the effectiveness of trifluridine/tipiracil (FTD/TPI), regorafenib, and chemotherapy rechallenge for third-line mCRC treatment. MATERIALS AND METHODS: We reviewed the medical records of 132 patients with mCRC treated with regorafenib, FTD/TPI, or a rechallenge with the initial chemotherapy regimen in a third-line setting from four different institutions. The primary end point was progression-free survival (PFS). Secondary end points were objective response rate and overall survival (OS) across the three treatment approaches. RESULTS: Twenty-nine patients received chemotherapy rechallenge, and 103 received FTD/TPI or regorafenib. Patients' characteristics were comparable, except for a lower number of left-sided primaries and KRAS wild-type tumors in the FTD/TPI-regorafenib group. The median PFS for the entire group was 3.0 months, and the median OS was 13.7 months. Chemotherapy rechallenge has resulted in a median PFS of 3.1 months and a median OS of 21.2 months, compared with 2.9 months (PFS) and 12.6 months (OS) for the FTD/TPI-regorafenib group. Multivariate analyses identified male sex and an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1 as independent prognostic factors for better PFS, whereas chemotherapy rechallenge, localized stage at diagnosis, and an ECOG PS of 0-1 were significant prognostic factors for better OS. CONCLUSION: This study suggests that chemotherapy rechallenge may provide a survival benefit in the third-line treatment of mCRC. However, patient characteristics, such as sex and ECOG PS, should also be considered in treatment decisions. Further prospective studies are required to confirm our findings.

An Unexpected Diagnosis of Second Primary Malignancy in a Breast Cancer Survivor: A Case Report.

BACKGROUND: Breast cancer survival rates are increasing more than ever with the development of better diagnostic and therapeutic techniques. Survivors of breast cancer have an increased risk of developing second primary malignancies, which may be mistaken for breast cancer recurrence and lead to delayed diagnosis and poor prognosis. CASE REPORT: We report a case of a 62-year-old female who presented with shortness of breath and bone pain. She had a history of left triple-positive invasive ductal carcinoma (T1N0M0) treated with bilateral skin-sparing mastectomy, adjuvant Taxotere, and trastuzumab-based therapy and then continued on trastuzumab and letrozole. She underwent imaging to explore the source of her symptoms at which new pulmonary nodules were discovered. During workup, she was found to have elevated tumor markers. They were initially suspected to be breast cancer recurrence metastases based on elevated tumor markers; however, further investigations confirmed that the nodules were a second primary lung adenocarcinoma with a different molecular profile. The patient had disease progression despite chemotherapy and eventually succumbed to her disease. CONCLUSION: This case highlights the importance of considering second primary malignancies in breast cancer survivors and utilizing advanced diagnostic modalities to efficiently diagnose such cases.