Palliative Primary Tumor Resection in Minimally Symptomatic Patients With Colorectal Cancer and Synchronous Unresectable Metastases

Palliative Primary Tumor Resection in Minimally Symptomatic Patients With Colorectal Cancer and Synchronous Unresectable Metastases Versus Chemotherapy Alone

Currently, the question remains whether palliative primary tumor resection could improve overall survival of minimally symptomatic patients with colorectal cancer and synchronous unresectable metastases. The aim of this study is to determine if there is an improvement in overall survival of palliative primary tumor resection followed by chemotherapy in minimally symptomatic patients with colorectal cancer and synchronous unresectable metastases compared to those of upfront chemotherapy/radiotherapy alone.

The present study is a single-center retrospective observational cohort study with a propensity score matching. Between 2016 and 2022 from our institutional database minimally symptomatic patients with colorectal cancer and synchronous unresectable metastases will be selected. Patients will be divided into two groups:

1. Surgical resection of the primary tumour before to systemic therapy
2. Systemic therapy without previous resection of the primary tumour. Propensity score matching (PSM) will be performed, to minimize the selection bias by adjusting variables that may affect the survival of patients. Categorical variables will be compared using the chi-square test or Fisher's exact test. Continuous variables will be compared using the Student's t-test or Mann-Whitney U test. Survival rate will be determined by using Kaplan-Meier analysis with a log-rank test. Univariate and multivariate analyses for survival will be conducted using Cox proportional hazard models. Statistical results will be considered significant at p values less than 0.05.

Inclusion Criteria:

1. Histologically confirmed colorectal adenocarcinoma
2. Resectable minimally symptomatic primary tumor with unresectable synchronous metastasis
3. Age ≥ 18 years
4. Informed consent

Exclusion Criteria:

1. Synchronous cancers
2. Carcinomatosis
3. Prior surgery, chemotherapy, radiation therapy for the primary tumor or distant metastases