Genetic Characteristics of Resectable Colorectal Cancer with Pulmonary Metastasis

Lung surveillance following colorectal cancer pulmonary metastasectomy: Utilization of clinicopathologic risk factors to guide strategy

BACKGROUND

Appropriately selected patients clearly benefit from resection of colorectal cancer (CRC) pulmonary metastases (PMs). However, there remains equipoise surrounding optimal chest surveillance strategies following pulmonary metastasectomy. We aimed to identify risk factors that may inform chest surveillance in this population.

METHODS

Patients who underwent CRC pulmonary metastasectomy were identified from a single institution's prospectively maintained surgical database. Clinicopathologic and genomic characteristics were collected. Patients were stratified by diagnosis of subsequent PM within 6 months of the index lung resection. Multivariate modeling was used to evaluate risk factors.

RESULTS

A total of 197 patients met the study's inclusion criteria, of whom 52.3% (n = 103) developed subsequent PM, at a median of 9.51 months following the index metastasectomy. Patients with KRAS alterations (odds ratio [OR], 3.073; 95% confidence interval [CI], 1.363-6.926; P = .007), TP53 alterations (OR, 3.109; 95% CI, 1.318-7.341; P = .010) were found to be at risk of PM diagnosis within 6 months of the index metastasectomy, while those with an APC alteration (OR, .218; 95% CI, 0.080-0.598; P = .003) were protected. Moreover, patients who received systemic therapy within 3 months of the initial PM diagnosis also were more likely to develop early lung recurrence (OR, 2.105; 95% CI, 0.971-4.563; P = .059).

CONCLUSIONS

Patients with KRAS alterations, TP53 alterations, and no APC alterations developed early recurrence in the lung following pulmonary metastasectomy, as did those who received chemotherapy after their initial PM diagnosis. As such, these groups benefit from early lung imaging after metastasectomy, as chest surveillance protocols should be based on patient-centered clinicopathologic and genomic risk factors.

Somatic mutations in colorectal cancer: regional experience

Introduction. Colorectal cancer is one of the most common malignant neoplasms in economically developed countries, ranking 3rd and 2nd in the structure of morbidity and mortality, respectively. Current knowledge about the molecular features of colorectal cancer is necessary to implement the principle of personalized therapy. Aim. To study regional features of tumor genomic landscape in colorectal cancer. Materials and methods. The retrospective study from 2019 to 2022 included 153 patients with stage IIV colorectal cancer aged 32 to 80 years, with a median of 63.8 years. DNA samples extracted from paraffin blocks of tumor tissue were analyzed using a real-time polymerase chain reaction. The study patients included 43.8% of males and 56.2% of females. Results. Somatic mutations were detected in 48.4% of patients. The maximum number of mutations was detected in the KRAS gene 60 (81%). The mutation rate was significantly higher in females versus males. KRAS mutations predominate in the colon compared to the rectum, accounting for 66.7 and 33.3%, respectively. In tumors of the right colon, these mutations were detected in 18.3% of cases, and in the left colon, 48.4%. NRAS mutations were found in 9.5% of cases, mainly in tumors of the left colon. BRAF mutations were diagnosed in 6 patients, 5 of them were women, and the tumors were localized in the right colon. The highest rate of KRAS mutations was observed in codons 12 and 13, accounting for 86.7% of cases. The G12V mutation occurred in the majority of patients (25%), followed by G12D (20%) and G12A (16.6%). Conclusion. Somatic mutations in RAS and BRAF genes in colorectal cancer were detected in 48.4% of patients in the Tambov region. Among them, there is a predominance of KRAS mutations 81% in females. KRAS oncogenic mutations are predictors of treatment response and prognosis.