Duration of FOLFOX Adjuvant Chemotherapy in High-Risk Stage II and Stage III Colon Cancer With Deficient Mismatch Repair

The effects of oxaliplatin-based adjuvant chemotherapy in high-risk stage II colon cancer with mismatch repair-deficient: a retrospective study

BACKGROUND

For high-risk stageIImismatch repair deficient (dMMR) colon cancers, the benefit of adjuvant chemotherapy remains debatable. The principal aim of this study was to evaluate the prognostic value of high-risk factors and the effect of oxaliplatin-based adjuvant chemotherapy among dMMR stageIIcolon cancers.

METHODS

Patients with stage II dMMR colon cancers diagnosed between June 2011 and May 2018 were enrolled in the study. Clinicopathological characteristics, treatment, and follow-up data were retrospectively collected. The high-risk group was defined as having one of the following factors: pT4 disease, fewer than twelve lymph nodes harvested (< 12 LNs), poorly differentiated histology, perineural invasion (PNI), lymphatic vascular invasion (LVI), or elevated preoperative carcinoembryonic antigen (CEA). The low-risk group did not have any risk factors above. Factors associated with disease-free survival (DFS) were included in univariate and multivariate Cox analyses.

RESULTS

We collected a total of 262 consecutive patients with stage II dMMR colon cancer. 179 patients (68.3%) have at least one high-risk factor. With a median follow-up of 50.1 months, the low-risk group was associated with a tended to have a better 3-year DFS than the high-risk group (96.4% vs 89.4%; P = 0.056). Both elevated preoperative CEA (HR 2.93; 95% CI 1.26-6.82; P = 0.013) and pT4 disease (HR 2.58; 95% CI 1.06-6.25; P = 0.037) were independent risk factors of recurrence. Then, the 3-year DFS was 92.6% for the surgery alone group and 88.1% for the adjuvant chemotherapy group (HR 1.64; 95% CI 0.67-4.02; P = 0.280). Furthermore, no survival benefit from oxaliplatin-based adjuvant chemotherapy was observed in the high-risk group and in the subgroups with pT4 disease or < 12 LNs.

CONCLUSIONS

These data suggests that not all high-risk factors have a similar impact on stage II dMMR colon cancers. Elevated preoperative CEA and pT4 tumor stage are associated with increased recurrence risk. However, oxaliplatin-based adjuvant chemotherapy shows no survival benefits in stage II dMMR colon cancers, either with or without high-risk factors.

Stage III deficient mismatch repair colon patients get greater benefit from earlier starting oxaliplatin-based chemotherapy regimen

We evaluate the prognostic value of chemotherapy and other prognostic factors on overall survival among colon patients with deficient mismatch repair (dMMR), and determine the optimum time to start chemotherapy after surgery. Data of 306 colon cancer patients with dMMR who received radical surgery were collected from three Chinese centers between August 2012 and January 2018. Overall survival (OS) was assessed with the Kaplan-Meier method and log-rank. Cox regression analysis were used to assess influencing prognosis factors. The median follow-up time for all patients was 45.0 months (range, 1.0-100). There was a nonsignificant OS benefit from chemotherapy for patients with stage I and stage II disease, including high-risk stage II disease (log-rank p: 0.386, 0.779, 0.921), and a significant OS benefit for patients with stage III and stage IV disease for receiving post-operation chemotherapy (log-rank p = 0.002, 0.019). Stage III patients benefitted from chemotherapy regimens that contained oxaliplatin (log-rank p = 0.004), and Starting chemotherapy with oxaliplatin treatment earlier resulted in better outcomes (95% CI 0.013-0.857; p = 0.035). Chemotherapy regimens containing oxaliplatin can prolong the survival time of stage III and IV dMMR colon cancer patients. This beneficial manifestation was more pronounced after starting chemotherapy treatment early post operation. High risk stage II dMMR colon patients including T₄N₀M₀ cannot benefit from chemotherapy.

Effects of deficient mismatch repair on the prognosis of patients with stage II and stage III colon cancer during different postoperative periods

Background

We evaluated the prognostic role of deficient mismatch repair (dMMR) systems in stage II and stage III colon cancer patients during different postoperative periods. We also assessed whether patients aged ≥75 could benefit from chemotherapy.

Methods

This retrospective study was conducted across three medical centers in China. Kaplan–Meier survival methods and Cox proportional hazards models were used to evaluate the differences in overall survival (OS) and disease-free survival (DFS) rates. Propensity score matching was performed to reduce imbalances in the baseline characteristics of the patients. Landmark analysis was performed to evaluate the role of dMMR during different postoperative periods.

Results

The median follow-up time for all patients was 45.0 months (25–75 IQR: 38.0–82.5). There was no significant OS (p = 0.350) or DFS (p = 0.752) benefit associated with dMMR for stage II and III patients during the first postoperative year. However, significant OS (p < 0.001) and DFS (p < 0.001) benefits were observed from the second postoperative year until the end of follow-up. These differences remained after propensity score matching. Moreover, chemotherapy produced no OS (HR = 0.761, 95% CI: 0.43–1.34, p = 0.341) or DFS (HR = 0.98, 95% CI: 0.51–1.88, p = 0.961) benefit for patients aged ≥75 years.

Conclusion

The benefits of dMMR in stage III patients were observed from the second postoperative year until the end of follow-up. However, the prognosis of patients with dMMR is not different from that of patients with proficient mismatch repair (pMMR) during the first postoperative year. In addition, elderly patients aged ≥75 years obtained no significant survival benefits from postoperative chemotherapy.

Adjuvant treatment of colon cancer with microsatellite instability - the state of the art

Adjuvant chemotherapy with fluoropyrimidine (FP) plus oxaliplatin in stage III resected colorecatal cancer (RCRC) resulted in a 30% relative reduction of disease recurrence risk and mortality. The presence of altered mismatch repair genes identify tumors with microsatellite instability (MSI) that have a better prognosis than stable tumors, but data about adjuvant chemotherapy benefit in this subgroup are compelling. We investigate the role of adjuvant therapy in resected MSI RCRC. The standard treatment is the association of FP plus oxaliplatin, while it can avoided in low risk stage II, thanks to its good prognosis. We propose a practice strategy to approach MSI RCRC in line with the current knowledge. In consideration of the dramatic results in chemorefractory MSI metastatic CRC, there are assumptions that immunotherapy can become a potential alternative to classical systemic therapies also in the adjuvant setting. We await the results of ongoing studies to draw further conclusions."

A Prognostic Nomogram of Colon Cancer With Liver Metastasis: A Study of the US SEER Database and a Chinese Cohort

Background

Among colon cancer patients, liver metastasis is a commonly deadly phenomenon, but there are few prognostic models for these patients.

Methods

The clinicopathologic data of colon cancer with liver metastasis (CCLM) patients were downloaded from the Surveillance, Epidemiology and End Results (SEER) database. All patients were randomly divided into training and internal validation sets based on the ratio of 7:3. A prognostic nomogram was established with Cox analysis in the training set, which was validated by two independent validation sets.

Results

A total of 5,700 CCLM patients were included. Age, race, tumor size, tumor site, histological type, grade, AJCC N status, carcinoembryonic antigen (CEA), lung metastasis, bone metastasis, surgery, and chemotherapy were independently associated with the overall survival (OS) of CCLM in the training set, which were used to establish a nomogram. The AUCs of 1-, 2- and 3-year were higher than or equal to 0.700 in the training, internal validation, and external validation sets, indicating the favorable effects of our nomogram. Besides, whether in overall or subgroup analysis, the risk score calculated by this nomogram can divide CCLM patients into high-, middle- and low-risk groups, which suggested that the nomogram can significantly determine patients with different prognosis and is suitable for different patients.

Conclusion

Higher age, the race of black, larger tumor size, higher grade, histological type of mucinous adenocarcinoma and signet ring cell carcinoma, higher N stage, RCC, lung metastasis, bone metastasis, without surgery, without chemotherapy, and elevated CEA were independently associated with poor prognosis of CCLM patients. A nomogram incorporating the above variables could accurately predict the prognosis of CCLM.