Impact of Primary Tumor Location on Demographics, Resectability, Outcomes, and Quality of Life in Finnish Metastatic Colorectal Cancer Patients (Subgroup Analysis of the RAXO Study)

Abstract

The primary tumor location (PTL) is associated with the phenotype, metastatic sites, mutations, and outcomes of metastatic colorectal cancer (mCRC) patients, but this has mostly been studied according to sidedness (right vs. left sided). We studied right colon vs. left colon vs. rectal PTL in a real-life study population (n = 1080). Health-related quality of life (HRQoL) was assessed multi-cross-sectionally with QLQ-C30, QLQ-CR29, EQ-5D, and 15D. A chi-square, Kaplan-Meier, and Cox regression were used to compare the groups. The PTL was in the right colon in 310 patients (29%), the left colon in 396 patients (37%), and the rectum in 375 patients (35%). The PTL was associated with distinct differences in metastatic sites during the disease trajectory. The resectability, conversion, and resection rates were lowest in the right colon, followed by the rectum, and were highest in the left colon. Overall survival was shortest for right colon compared with left colon or rectal PTL (median 21 vs. 35 vs. 36 months), with the same trends after metastasectomy or systemic therapy only. PTL also remained statistically significant in a multivariable model. The distribution of symptoms varied according to PTL, especially between the right colon (with general symptoms of metastases) and rectal PTL (with sexual- and bowel-related symptoms). mCRC, according to PTL, behaves differently regarding metastatic sites, resectability of the metastases, outcomes of treatment, and HRQoL.

Keywords: metastasectomy; metastatic colorectal cancer; primary tumor location; quality of life; resectability.

Figure 1

Study design, patient flow, health-related quality of life (HRQoL) questionnaires, post-resection (within 6 months after metastasectomy and/or local ablative therapy (LAT) including adjuvant-like treatment), remission (more than 6 months after metastasectomy and/or LAT), systemic therapy (mean of neoadjuvant/conversion, first-, second- and later-line), best supportive care (after ending active cancer treatment).

Figure 2

Frequency of metastatic sites of the nine most common metastatic sites at baseline and during disease trajectory (presented to 60+ months) divided by primary tumor location.

Figure 3

Technical resectability assessment at the tertiary center in Helsinki and the upfront resectable and converted proportions, proportions that underwent resection or ablation according to primary tumor location.

Figure 4

Overall survival according to primary tumor location. All patients (A), systemic therapy only (B), and metastasectomy and/or LAT (C).

Figure 5

Progression-free survival for ‘systemic therapy only’ (A), and relapse-free survival after first metastasectomy and/or local ablative therapy according to primary tumor location (B).

Figure 6

Symptom burden as sum of 26 symptom scales (0 no symptoms to 100 most symptoms, theoretical maximum 2600) measured with the QLQ-C30 and QLQ-CR29 during different treatment phases according to primary tumor location.

Figure 7

Comparison of symptom scales from QLQC30 during four treatment phases: post-resection ((A), within 6 months after metastasectomy and/or local ablative therapy (LAT) including adjuvant-like treatment), remission ((B), more than 6 months after metastasectomy and/or LAT), systemic therapy ((C), mean of neoadjuvant/conversion, first-, second- and later-line), best supportive care ((D), after ending active cancer treatment). Statistically significant differences between primary tumor locations are marked with brackets.