Association Between Height and Clinical Outcome in Metastatic Colorectal Cancer Patients Enrolled Onto a Randomized Phase 3 Clinical Trial: Data From the FIRE-3 Study.

Background: Previous studies have found significant relationships between height and colorectal cancer (CRC) risk. Increased growth has been associated with activated pathways such as insulin-like growth factor 1. This study examined the impact of height on outcomes in metastatic CRC patients enrolled onto the FIRE-3 study, a randomized phase 3 clinical trial.

Patients And Methods: A total of 695 patients with metastatic CRC were studied and height was measured in centimeters. Male patients were grouped as ≤ 165, 166-175, 176-185, and ≥ 186 cm in height; female patients were grouped as ≤ 154, 155-164, 165-174, and ≥ 175 cm in height. Primary end point was overall survival (OS); secondary end point was progression-free survival.

Results: When patients' heights were categorized into 4 groups, the tallest group showed a worse OS compared to the shortest group; however, there was no linear relationship between height and OS. To investigate this, we showed the association between height as a continuous variable and OS. Patients shorter than 172 cm had a worse OS as their height decreased. Patients taller than 172 cm had a worse OS as their height increased. Moreover, patients with heights between 165 and 179 cm had a better OS compared to other patients (P = .05). This effect was independent of treatment arm and gender.

Conclusion: Patients shorter than 165 cm and taller than 179 cm have a worse OS, while those between 165 and 179 cm have a better OS. Hence, clinicians should consider height as an important prognostic factor when treating metastatic CRC patients. Future prospective studies are warranted to shed light on the mechanisms underlying the worse OS in taller patients.