China special issue on gastrointestinal tumors-Radiological features of pathological complete response in mismatch repair deficient colorectal cancer after neoadjuvant PD-1 blockade: A post hoc analysis of the PICC phase II trial

Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy.     

Clinical and pathological predictors of recurrence in breast cancer patients achieving pathological complete response to neoadjuvant chemotherapy

IntroductionDespite the excellent prognosis associated with pathological complete response (pCR) to neoadjuvant chemotherapy (NAC), some patients still develop recurrence. Here, we investigated the outcomes of breast cancer patients with pCR, as well as the clinical and pathological predictors of cancer recurrence in these patients.Materials and methodsOf the 1599 breast cancer patients treated with NAC, we evaluated 394 patients who achieved pCR between January 2007 and December 2016. pCR was defined as no evidence of invasive cancer in breast. Residual in situ ductal and axillary lymph node diseases were not considered. We analyzed the outcomes using the Kaplan–Meier method. We assessed the association of clinical and pathological predictors with cancer recurrence using the cox proportional hazards regression model.ResultsThe median follow-up time was 63 months. The 5-year disease-free survival rate was 92.3%. Cancer recurrence was observed in 28 patients (7.1%): local recurrence 8 patients (2.0%), visceral metastasis 10 patients (2.5%), and brain metastasis 10 patients (2.5%). Brain metastases were found in patients with HER2 type breast cancer. The significant predictors of cancer recurrence were HER2 positivity (p = 0.04), clinical tumor size (p < 0.01), and lymph node metastasis (p < 0.01) before NAC on univariate analysis and only lymph node metastasis on multivariate analysis.ConclusionPatients achieving pCR to NAC showed excellent outcomes. Advanced clinical stage, large tumor size, presence of lymph node metastasis, and HER2 positivity before NAC were identified as significant predictors of cancer recurrence. Residual in situ ductal and lymph node diseases after NAC were not significant predictors.