Pre-treatment Platelet Counts Associated With Prognosis in Stage 2-3 Rectal Cancer

Platelet counts at the time of initial diagnosis had prognostic value for patients with stage II or III rectal adenocarcinoma receiving neoadjuvant treatment, a study presented at American Association for Cancer Research (AACR) Annual Meeting 2016 has shown.¹

Because thrombocytosis is often associated with malignancies and has been confirmed as a negative prognostic factor in various cancers, researchers sought to investigate whether pre-treatment elevated platelet counts have predictive value in outcomes in patients with stage II or III rectal adenocarcinoma who received neoadjuvant treatment.

For the study, researchers evaluated platelet counts in 51 patients who had complete follow-up data available on progression and survival, as well as on pathologic outcome at the time of surgery. Researchers compared the pathologic response following neoadjuvant treatment of patients with lower platelet counts between 150-300 x 10⁹/L with that of patients with higher platelet counts greater than 300 x 10⁹/L.

Results showed that patients with lower platelet counts were more likely to demonstrate a good or complete response to neoadjuvant treatment than patients with higher platelet counts (P = .015).

Researchers also found a significant difference in the carcinoembryonic antigen (CEA) level at presentation between patients who exhibited a good or complete response and those who had a minimal to moderate response or no response. Patients who achieved a good or complete response had a higher likelihood of presenting with a CEA level less than 5 (P = .00066). This finding suggested that pre-treatment CEA level holds prognostic value, as well.

However, the study demonstrated no significant different in overall survival or progression-free survival between the 2 groups of patients.

Reference

1. Voutsadakis I, Steele M. Pre-treatment platelet counts as a prognostic factor in stage II and III rectal adenocarcinoma. Poster presentation at: AACR Annual Meeting 2016; April 16-20, 2016; New Orleans, LA.