Complete pathological response after chemotherapy or immune checkpoint inhibitors in deficient MMR metastatic colorectal cancer: Results of a retrospective multicenter study

About 5% of the patients with metastatic colorectal cancers (mCRC) present microsatellite instability (MSI)/deficient mismatch repair system (dMMR). While metastasectomy is known to improve overall and progression-free survival in mCRC, specific results in selected patients with dMMR/MSI mCRC are lacking. Our study aimed to describe metastasectomy results, characterize histological response and evaluate pathological complete response (pCR) rate in patients with dMMR/MSI mCRC. We retrospectively reviewed data from all consecutive patients with dMMR/MSI mCRC who underwent surgical metastasectomy between January 2010 and June 2021 in 17 French centers. Primary outcome was to assess the pCR rate defined by tumor regression grade (TRG) 0. Secondary endpoints included relapse-free survival (RFS) and overall survival (OS), and explored TRG as predictive factor for RFS and OS. Among the 88 patients operated, 109 metastasectomies were performed in 81 patients after neoadjuvant treatment [chemotherapy ± targeted therapy (CTT): 69, 85.2%; immunotherapy (ICI): 12, 14.8%], and pCR was achieved in 13 (16.1%) patients. Among the latter, pCR rate were 10.2% in the patients having received CTT (N = 7) and 50.0% in the patients treated with ICI (N = 6). Radiological response did not predict TRG. With a median follow-up of 57.9 (IQR 34.2-81.6) months, median RFS was 20.2 (15.4-not reached) months, median OS was not reached. Major pathological responses (TRG0 + TRG1) were significantly associated with longer RFS (HR 0.12, 95% CI 0.03-0.55; P = .006). The pCR rate of 16.1% achieved with neoadjuvant treatment in patients with dMMR/MSI mCRC is consistent with previously reported rates in pMMR/MSS mCRC. Immunotherapy showed better pCR rate than chemotherapy ± targeted therapy. Further prospective trials are needed to validate immunotherapy as neoadjuvant treatment in resectable/potentially resectable dMMR/MSI mCRC and identify predictive factors for pCR.

Is There a Benefit of Oxaliplatin in Combination with Neoadjuvant Chemoradiotherapy for Locally Advanced Rectal Cancer? An Updated Meta-Analysis

BACKGROUND

Neoadjuvant fluoropyrimidine (5FU or capecitabine)-based chemoradiotherapy (CRT) has been considered the standard of care for locally advanced rectal cancer (LARC). Whether addition of oxaliplatin (OXP) will further improve clinical outcomes is still unclear.

METHODS

To identify clinical trials combining oxaliplatin in preoperative CRT or perioperative chemotherapy for LARC published until March 2021, we searched PubMed and the Cochrane Library. We also searched for relevant ASCO conference abstracts. The primary endpoint was disease-free survival (DFS). Data were extracted from every study to perform a meta-analysis using Review Manager (version 5.3).

RESULTS

A total of seven randomized clinical trials (ACCORD-12, CARO-AIO-04, FOWARC, JIAO, NSABP, PETACC-6, and STAR-01) with 5782 stage II or III rectal cancer patients were analyzed, including 2727 patients with OXP + 5FU regimen and 3055 patients with 5FU alone. Compared with the 5FU alone group, the OXP + 5FU regimen improved DFS (HR = 0.90, 95% CI: 0.81-0.99, p = 0.03) and pathologic complete response (pCR) (OR = 1.21, 95% CI: 1.07-1.37, p = 0.002). Patients treated with the OXP + 5FU regimen had significantly less metastatic progression (OR = 0.79; 95% CI, 0.67 to 0.94; p = 0.007). Considering adverse events (AEs), there was more grade 3-4 diarrhea with OXP + 5FU (OR = 2.41, 95% CI: 1.74-3.32, p < 0.00001). However, there were no significant differences grade 3-4 hematologic AEs (OR = 1.16, 95% CI: 0.87-1.57, p = 0.31).

CONCLUSIONS

Our meta-analysis with long-term results from the randomized studies showed a benefit of the addition of OXP + 5FU regiment in terms of DFS, metastatic progression, and pCR rate that did not translate to improved OS.

First-line immune-checkpoint inhibitor plus chemotherapy versus chemotherapy alone for extensive-stage small-cell lung cancer: a meta-analysis

Introduction

Platin-based chemotherapy (CT) has long been the first-line standard-of-care for patients with extensive-stage small-cell lung cancer (ES-SCLC). Adding immune-checkpoint inhibitor(s) to CT (ICI+CT) in this setting is an option of interest, although its benefit is apparently modest.

Methods

This meta-analysis was conducted on randomized trials comparing first-line ICI+CT versus CT alone for ES-SCLC. Outcomes included overall survival (OS), progression-free survival (PFS), objective response rate (ORR), response at 12 months and adverse events (AEs). Subgroup analyses were computed according to the immunotherapy used, performance status (PS), age, platinum salt, liver metastases and brain metastases at diagnosis.

Results

The literature search identified one randomized phase II (ECOG-ACRIN-5161) and four phase III trials (CASPIAN, IMPOWER-133, KEYNOTE-604 and Reck et al. 2016) that included 2775 patients (66% males, 95% smokers, median age: 64 years, PS = 0 or 1). ICI+CT was significantly associated (hazard ratio [95% confidence interval]) with prolonged OS [0.82 (0.75-0.89); p <  0.00001] and PFS [0.81 (0.75-0.87); p <  0.00001], with OS benefits for anti-PD-L1 [0.73 (0.63-0.85); p < 0.0001] or anti-PD-1 [0.76 (0.63-0.93); p < 0.006] but not for anti-CTLA-4 [0.90 (0.80-1.01), p = 0.07]. ORRs for ICI+CT or CT alone were comparable [odds ratio 1.12 (0.97-1.00); p = 0.12], but responses at 12 months favored ICI+CT [4.16 (2.81-6.17), p < 0.00001]. Serious grade-3/4 AEs were more frequent with ICI+CT [odds ratio 1.18 (1.02-1.37); p = 0.03]. Compared with CT, no ICI+CT benefit was found for ES-SCLC with brain metastases at diagnosis [HR 1.14 (0.87-1.50); p = 0.34].

Conclusions

First-line ICI+CT appears to be superior to CT alone for ES-SCLC except for patients with brain metastases at diagnosis.

Upfront association of carboplatin plus pemetrexed in patients with brain metastases of lung adenocarcinoma

Approximately 10% of patients with non-small cell lung cancer (NSCLC) have brain metastases at the time of diagnosis. When surgical resection is not possible, whole brain radiotherapy is the standard of care, with a cerebral response rate of approximately 30%. We report our experience with an upfront association of carboplatin and pemetrexed (areas under the curve, 5 and 500 mg/m(2), respectively), every 3 weeks, in 30 patients presenting with newly diagnosed brain metastases and NSCLC. Cerebral MRIs were performed every 6-9 weeks. The radiologic response rates were assessed according to Response Evaluation Criteria in Solid Tumors. Overall survival was also determined. Twenty-six patients were evaluable for response, and the objective cerebral response rate (complete and partial response) in the intent-to-treat population was 40% (12 of 30 patients). Event-free survival was 31 weeks, and median overall survival was 39 weeks. The upfront association of carboplatin plus pemetrexed allows simultaneous treatment of cerebral and systemic disease in patients with NSCLC with newly diagnosed brain metastases and appears to be particularly interesting in terms of radiologic response and overall survival. Further clinical studies are warranted.

Duration of adjuvant chemotherapy for patients with non-metastatic colorectal cancer

BACKGROUND

Surgery of primary tumour is the backbone of colorectal cancer treatment (CRC). But in stage III cancer, metastatic or local relapse is often observed (50%). So, adjuvant treatment is always considered in this setting. The best treatment duration of hypothetic disease is not easy to define. Adjuvant chemotherapy for CRC actually lasts 6 months. The choice of optimal duration is based upon old studies using 5-fluorouracil (5FU). During the last ten years, results of major randomized controlled studies (RCTs) comparing different durations of treatments and different schedules in adjuvant setting were published. Several studies compared a 6-month chemotherapy with a longer treatment. Conversely, a single study by Chau et al compared a 6 month chemotherapy with continuous treatment lasting 3 months. But the optimal duration of these chemotherapies could be challenged. Even though the optimal duration of chemotherapy in CRC is a major issue, it has never been answered adequately.

OBJECTIVES

To evaluate the optimal duration of adjuvant treatment, we performed a meta-analysis of all RCTs comparing two durations of adjuvant treatment, 6 months versus 9 to 12 months.

SEARCH STRATEGY

Publications were identified from PubMed (February 28th, 2009), Embase, and the Cochrane Database of Clinical Controlled Trials (CENTRAL) in the Cochrane Library 2009 issue 1. Reviews and books were also scrutinized. Abstracts were reviewed from ASCO annual meetings proceedings from 1998 to 2009.

SELECTION CRITERIA

Patients with surgically resected colorectal cancer with high risk of recurrence.

DATA COLLECTION AND ANALYSIS

Several RCTs compared shorter versus longer durations of chemotherapy, 6 studies for overall survival (OS) and 7 studies for relapse free survival (RFS), for a total of 10326 patients, mean age 63.1 years, including 9826 colon and 500 rectum cancers.

MAIN RESULTS

Treatments were always based on 5-FU. Two studies were excluded, an epidemiological study and a study comparing continuous treatment during 3 months with conventional chemotherapy during 6 months. The later because it compared 2 durations less than or equal to 6 months. Shorter duration of chemotherapy (3-6 months) compared with longer duration (9-12 months) was not associated to poorer RFS (RR =0.96, 95% CI : 0.90-1.02) and OS (RR = 0.96 ; 95% CI : 0.91-1.02).

AUTHORS' CONCLUSIONS

The present meta-analysis confirmed that adjuvant chemotherapy of CRC should not last for more than 6 months. Prolonged duration would result in lower benefit to risk ratio. However, the results do not make it possible to favour either 3 or 6 month durations. They should help design a future RCT comparing different durations of continuous treatment.

Does microsatellite instability predict the efficacy of adjuvant chemotherapy in colorectal cancer? A systematic review with meta-analysis

BACKGROUND

Microsatellite instability (MSI) status in predicting the efficacy of adjuvant chemotherapy in colorectal cancer remains controversial.

MATERIALS AND METHODS

Studies were identified through PubMed, Embase and ASCO proceedings with a combination of keywords (colorectal cancer, chemotherapy and MSI).

RESULTS

A MA was performed for treated and non-treated MSI population on seven studies. Statistical calculations were performed on 7 studies representing 3690 patients; mean age: 65.5 years; 810 stage II and 2444 stage III (75%). MSI-high (MSI-H) was found in 454 patients (14% of the global population), and microsatellite stable (MSS) in 2871. A total of 1444 patients received 5-fluorouracil (5FU)-based chemotherapy, whereas 1518 patients did not. For MSI-H patients, there was no statistically significant difference for RFS whether or not they received chemotherapy (5 studies); HR RFS: 0.96 (95% confidence interval (CI): 0.62-1.49); HR OS (6 studies): 0.70 (95% CI: 0.44-1.09; p=0.12). Elsewhere, we found a significant interaction between MSI status (MSI-H or MSS) and therapeutic status suggesting a lesser benefit for MSI-H than for MSS patients (HR interaction RFS: 0.77 (95% CI: 0.67-0.87)).

CONCLUSION

We found similar RFS for treated and untreated MSI-H patients, showing that MSI-H status, in addition to being a good prognostic factor is also a predictive factor of non response.

Microsatellite instability does not predict the efficacy of chemotherapy in metastatic colorectal cancer. A systematic review and meta-analysis

BACKGROUND

Microsatellite Instability (MSI) status is a good prognostic factor for colorectal cancer (CRC) but its predictive value for chemosensitivity remains controversial. A previous meta-analysis (MA) in the adjuvant setting showed that MSI-high (H) status did not predict the efficacy of chemotherapy. The predictive value of MSI status on the effect of metastatic chemotherapy was investigated by MA.

PATIENTS AND METHODS

Studies were identified by electronic search through PubMed, Embase and ASCO proceedings online databases, using several key words (colorectal cancer, chemotherapy, microsatellite instability). For each study, the ratio of response rate (RR), complete (CR) and partial response (PR) divided by stable disease and progression was calculated. From 190 articles and 100 abstracts, only eight independent studies were selected. The data were analysed with a random-effect model (due to heterogeneity between studies) using EasyMA software. Statistical calculations were performed on six studies representing 964 patients (mean age 63 years; 91 MSI-H; 873 microsatellite stable (MSS) tumours). A total of 287 patients received 5-fluorouracil (5FU)-based chemotherapy, whereas 678 patients received combinations of 5FU or capecitabine with oxaliplatin and/or irinotecan.

RESULTS

No benefit of metastatic chemotherapy in terms of RR for MSI-H patients compared with MSS patients was found. The global hazard ratio (HR) for RR was 0.82 (95% confidence interval, CI: 0.95; 0.65-1.03; p=0.09).

CONCLUSION

MSI status does not predict the effect of chemotherapy which is similar in MSI-H and MSS metastatic CRC tumours.

Microsatellite instability: a predictive marker in metastatic colorectal cancer?

Microsatellite instability (MSI) status is a good prognostic factor for colorectal cancer (CRC), but its predictive value for chemosensitivity remains controversial. We recently performed a meta-analysis (MA) in adjuvant setting showing that MSI high (MSI-H) status did not predict the efficacy of chemotherapy. Studies were identified by electronic search through PubMed, Embase and ASCO proceedings online databases, using several keywords (colorectal cancer, chemotherapy, microsatellite instability). For each study, we calculated the ratio of response rate, complete and partial responses divided by stable disease and progression. Our MA dealt with the predictive value of MSI status on the effect of metastatic chemotherapy using various combinations of 5FU, oxaliplatin or CPT11. From 159 articles and 76 abstracts, we selected only seven independent studies. Data were analysed with a random-effect model (due to heterogeneity between studies) using EasyMA software. Statistical calculations were performed on five studies representing 860 patients (mean age 63 years; 87 MSI-H; 733 microsatellite stable [MSS] tumors). A total of 287 patients received 5FU-based chemotherapy, whereas 574 patients received combinations of 5FU or capecitabine with oxaliplatin and/or irinotecan. Our MA found no benefit of metastatic chemotherapy in terms of response rate for MSI-H patients compared with MSS patients. The global hazard ratio for response rate was 0.83 (95% confidence interval: 0.95; 0.65-1.05; p = 0.11). In conclusion, MSI status did not predict the effect of chemotherapy for metastatic CRC. Metastatic chemotherapy had a similar effect on both MSI-H or on MSS tumors.

Is sentinel lymph node mapping in colorectal cancer a future prognostic factor? A meta-analysis

The diagnostic value of sentinel lymph node mapping (SLNM) in patients with colorectal cancer (CRC) is controversial. Prognostic factors for CRC must be detected to improve its treatment. A PubMed query (key words: colorectal cancer, sentinel node) provided 182 studies on the sentinel lymph node (SLN) for CRC, the abstracts of which were reviewed. Altogether, 48 studies dealing with the diagnostic value of SLNM were selected from PubMed, and 6 other studies were retrieved from reviews. We compared the diagnostic value of SLNM with that of conventional histopathologic examination. We used the diagnostic accuracy odds ratio (DAOR) method. Because of significant heterogeneity, we chose the random effect model (Der Simonian and Laird). Statistics were performed on 33 studies, including 1794 patients (1201 colon and 332 rectum cancers). The mean SLNM failure rate was 10%. The global sensitivity and specificity of the SLNM were, respectively, 70% and 81%. The pooled DAOR was 10.7 (95% confidence interval 7.0-16.5). That means that a patient whose SLN is invaded has 10.7 times more risk to be node-positive than an SLN-negative patient. Lymphatic mapping appears to be readily applicable to CRC. One of the main reasons for the heterogeneity is the performance of the SLNM by Saha et al., whose data had better sensitivity (90%) than those in other studies. The SLNM technique should be better standardized in future studies. Understanding the cause of false-negative SLNs (9%) is a major issue to resolve before routinely using this technique in CRC management. The prognostic implication of micrometastases found in SLNs requires further evaluation.

Breast Cancer Associated With Idiopathic Thrombocytopenic Purpura

The aim of this study was to define the characteristics of patients with idiopathic thrombocytopenic purpura (ITP) and breast cancer and discuss the relationship between these two diseases. Ten patients treated for breast cancer and presenting with ITP were screened for this study. The diagnosis of breast cancer was confirmed by biopsy or surgical sample. The diagnosis of ITP was defined by 1) platelet count less than 140.10(9)/l with normal or increased number of megakaryocytes on bone marrow aspirate, 2) after exclusion of thrombocytopenia-induced medication or disorders, and 3) absence of splenomegaly. ITP was diagnosed before breast cancer in three cases, concomitantly in three, and after the diagnosis of breast cancer in four cases. Platelet count and breast cancer showed an independent course in seven cases, and appeared to be correlated in the other three patients. No correlation was found between the development of ITP and tumor characteristics. In contrast, the median platelet count was 15.10(9)/l (range 3-26) for the 3 patients with a correlation between the course of ITP and breast cancer evolution and 70.10(9)/l (range 20-90) for the other cases (p = 0.05, Mann-Whitney U test). Breast cancers are associated with ITP, with a parallel course of the two diseases in one third of cases. This may suggest tumor-induced immunologic thrombocytopenia.