Colorectal Surgery

Guideline-concordant trimodality therapy halves mortality in older stage III rectal cancer but is uncommon

This SEER-Medicare analysis included 3962 adults with stage III rectal cancer diagnosed between 2007 and 2018. Guideline-based care required chemoradiation within 6 months of diagnosis, surgery within 6 months after chemoradiation, and postoperative chemotherapy. Only 25.1% received all guideline-based treatments, although 43.1% had a Charlson Comorbidity Index of zero. Guideline-based care was associated with substantially better overall survival (HR 0.55, 95% CI 0.49–0.60) and cancer-specific survival (HR 0.59, 95% CI 0.48–0.73). 1

Tissue-free methylation ctDNA MRD assay shows high specificity and strong prognostic value after CRC resection

This GALAXY substudy validated a tumor-agnostic methylation-based ctDNA MRD assay (Latitude) in 195 colorectal cancer patients with 1230 timepoints. Postoperative ctDNA positivity predicted markedly worse disease-free survival in both MRD (HR 10.0, P<0.001) and surveillance windows (HR 31.9, P<0.001). In the MRD window, sensitivity was 58.5%, while specificity among patients not receiving adjuvant chemotherapy was 100%. Longitudinally, relapse detection sensitivity reached 84.4%, with high patient-level (92.1%) and sample-level (97.2%) specificity and a median 4.6-month lead time. 2

Sintilimab plus long-course CRT achieves high pCR in Immunoscore-selected pMMR locally advanced rectal cancer

The single-arm phase II SILAR trial enrolled 46 treatment-naïve patients with pMMR locally advanced rectal cancer and intermediate or high Immunoscore. Patients received six cycles of mFOLFOX6 with long-course radiotherapy (50 Gy in 25 fractions), adding sintilimab during cycles two through six, followed by surgery. The pathologic complete response rate was 65.2% overall, higher in high Immunoscore tumors (85.7%) than intermediate Immunoscore tumors (61.5%). Secondary outcomes included an R0 resection rate of 97.8% and an objective clinical response rate of 93.5%. 3

APPAC 10-year follow-up: antibiotics remain safe initial therapy but 44% ultimately require appendectomy

The APPAC trial randomized 530 adults with CT-confirmed uncomplicated appendicitis to open appendectomy or antibiotics at six Finnish hospitals. At 10 years, among 253 assessable patients initially assigned antibiotics, histologically confirmed appendicitis recurrence occurred in 37.8%. The cumulative appendectomy rate in the antibiotic group reached 44.3% over 10 years. Cumulative complication rates favored antibiotics (8.5%) compared with appendectomy (27.4%). 4