Long-Term Outcomes of dMMR/MSI-H Rectal Cancer Treated With Anti-PD-1-Based Immunotherapy as Curative-Intent Treatment.

BACKGROUND: Neoadjuvant anti-PD-1 therapy has shown encouraging efficacy in patients with deficient DNA mismatch repair (dMMR)/microsatellite instability-high (MSI-H) locally advanced rectal cancer (LARC), which suggests its potential as a curative-intent therapy and a promising treatment option for organ preservation. We aimed to investigate the long-term outcomes of patients with dMMR/MSI-H LARC who experienced clinical complete response (cCR) after anti-PD-1 therapy. METHODS: We retrospectively analyzed patients with dMMR/MSI-H LARC who achieved cCR and received nonoperative management following neoadjuvant anti-PD-1-based treatment from 4 Chinese medical centers. Patients were followed up for at least 1 year after they achieved cCR, their clinical data were collected, and survival outcomes were analyzed using the Kaplan-Meier method. RESULTS: A total of 24 patients who achieved cCR and received nonoperative management from March 2018 to May 2022 were included, with a median age of 51.0 years (range, 19.0-77.0 years). The median treatment course to reach cCR was 6.0 (range, 1.0-12.0). Fifteen patients (62.5%) continued their treatments after experiencing cCR, and the median treatment course was 17.0 (range, 3.0-36.0). No local regrowth or distant metastasis was observed in a median follow-up time of 29.1 months (range, 12.6-48.5 months) after cCR. The 3-year disease-free and overall survivals were both 100%. CONCLUSIONS: Patients with dMMR/MSI-H locally advanced or low-lying rectal cancer who achieved cCR following anti-PD-1-based therapy had promising long-term outcomes. A prospective clinical trial with a larger sample size is required to further validate these findings.

Long-term outcomes of pelvic exenterations for gynecological malignancies: a single-center retrospective cohort study.

BACKGROUND: Recently, with the advancement of medical technology, the postoperative morbidity of pelvic exenteration (PE) has gradually decreased, and it has become a curative treatment option for some patients with recurrent gynecological malignancies. However, more evidence is still needed to support its efficacy. This study aimed to explore the safety and long-term survival outcome of PE and the feasibility of umbilical single-port laparoscopic PE for gynecologic malignancies in a single medical center in China. PATIENTS AND METHODS: PE for gynecological cancers except for ovarian cancer conducted by a single surgical team in Sun Yat-sen University Cancer Center between July 2014 and December 2019 were included and the data were retrospectively analyzed. RESULTS: Forty-one cases were included and median age at diagnosis was 53 years. Cervical cancer accounted for 87.8% of all cases, and most of them received prior treatment (95.1%). Sixteen procedures were performed in 2016 and before, and 25 after 2016. Three anterior PE were performed by umbilical single-site laparoscopy. The median operation time was 460 min, and the median estimated blood loss was 600 ml. There was no perioperative death. The years of the operations was significantly associated with the length of the operation time (P = 0.0018). The overall morbidity was 52.4%, while the severe complications rate was 19.0%. The most common complication was pelvic and abdominal infection. The years of surgery was also significantly associated with the occurrence of severe complication (P = 0.040). The median follow-up time was 55.8 months. The median disease-free survival (DFS) was 17.9 months, and the median overall survival (OS) was 25.3 months. The 5-year DFS was 28.5%, and the 5-year OS was 30.8%. CONCLUSION: PE is safe for patient who is selected by a multi-disciplinary treatment, and can be a curative treatment for some patients. PE demands a high level of experience from the surgical team. Umbilical single-port laparoscopy was a technically feasible approach for APE, meriting further investigation.

Efficacy of PD-1 inhibitors for colorectal cancer and polyps in Lynch syndrome patients.

BACKGROUND: Programmed death-1 (PD-1) inhibitor is effective for colorectal cancer (CRC) with deficient mismatch repair (dMMR) or high microsatellite instability (MSI-H). We aimed to explore its effects on CRCs and colonic polyps in Lynch syndrome (LS) patients. METHODS: LS patients with CRC who had evaluable tumours and received at least 2 cycles of PD-1 inhibitors were retrospectively included. PD-1 inhibitors were given as a monotherapy or in combination with other therapies, including anticytotoxic T-lymphocyte-associated antigen-4 treatment, radiotherapy, chemotherapy, and targeted therapy. Correlations of treatment responses with clinicopathological characteristics and genomic profiles were analysed. RESULTS: A total of 75 LS patients were included, with a median age of 39 years. The median duration of follow-up was 27 months (range, 3-71). The objective response rate (ORR) was 70.7%, including 28.0% (n = 21) complete responses and 42.7% (n = 32) partial responses. Four of five cases of LS CRCs displaying proficient MMR (pMMR) or microsatellite stable (MSS) were not responsive. Mucinous/signet-ring cell differentiation was associated with a lower ORR (P = 0.013). The 3-year overall survival and progression-free survival were 91.2% and 82.2%, respectively. A polyp was detected in 26 patients during surveillance. Seven adenomas disappeared after treatment, and they were all larger than 7 mm. CONCLUSION: PD-1 inhibitors are highly effective for dMMR and MSI-H LS CRCs, but not for pMMR or MSS LS CRCs or mucinous/signet-ring cell CRC. Large LS adenomas may also be eliminated by anti-PD-1 treatment. DATA AVAILABILITY STATEMENT: Due to the privacy of patients, the related data cannot be available for public access but can be obtained from Pei-Rong Ding (dingpr@sysucc.org.cn) upon reasonable request. The key raw data have been uploaded to the Research Data Deposit public platform (www.researchdata.org.cn).

Surgical Outcome and Long-Term Survival of Conversion Surgery for Advanced Gastric Cancer.

BACKGROUND: The present study aims to report the surgical outcome and long-term survival of conversion surgery and clarify its role in advanced gastric cancer. PATIENTS AND METHODS: A total of 95 primary advanced gastric adenocarcinoma patients who underwent systemic chemotherapy and conversion surgery were reviewed retrospectively. The survival of conversion surgery was analyzed by Cox regression and the Kaplan-Meier method. Surgical outcomes were analyzed according to the Clavien-Dindo classification. RESULTS: The median survival time (MST) of the 95 patients was 26.8 months, and the postoperative MST was 19.3 months. The MSTs of the patients in categories 1, 2, 3, and 4 were 28.8, 25.5, 43.6, and 11.3 months, respectively. The MSTs of the patients who underwent R0 resection (47 cases) and R1/2 resection (48 cases) were 49.3 months and 21.9 months, respectively. The MST of patients treated with total gastrectomy was shorter (21.9 months) than that of patients who underwent proximal (55.0 months) or distal (46.3 months) gastrectomy. Patients who received more than 6 cycles of induction chemotherapy had a longer MST than patients who received 3-5 cycles or 1-2 cycles (MST: 55.0 months versus 21.1 months versus 21.7 months). The incident postoperative complications and postoperative mortality rates were 10.5% and 1.1%, respectively. CONCLUSIONS: Advanced gastric cancer patients may obtain a survival benefit from conversion surgery, except category 4. Performing a sufficient number of cycles of induction chemotherapy (usually ≥ 6 cycles) is recommended. Surgical oncologists should perform R0 resection and avoid total gastrectomy.