Pneumococcal serotype distribution and outcomes in cancer patients with community-acquired pneumonia: A prospective study using the 15-valent pneumococcal conjugate vaccine serotype specific urinary antigen detection assay.

OBJECTIVES

Cancer patients with pneumococcal community-acquired pneumonia (CAP) have higher mortality than the general population. Data on pneumococcus serotype distribution in this population are limited. We evaluated pneumococcal serotypes using a 15-valent pneumococcal conjugate vaccine (PCV15) serotype-specific urinary antigen detection (SSUAD) in cancer patients with CAP.

METHODS

Prospective observational study in adult cancer patients with CAP at MSKCC (1/1/2023-1/31/2024). Streptococcal urine antigen (SUA) testing was performed in-house. Remnant urine samples were tested by PCV-15 SSUAD at Q2 laboratories. Blood and respiratory culture results were captured within 7 days of SUA.

RESULTS

Of 912 patients with CAP (median age=67), 94.6% were hospitalized. Forty-one (4.5%) had pneumococcal pneumonia by SUA and SSUAD (N = 35), sputum culture (N = 2), or blood culture (N = 7). By urine antigen, SUA was positive in 15, SSUAD in 19, and one in both. The most common serotype by SSUAD was 7F (24.3%), and 35% had ≥2 serotypes. Only 26.9% had received any pneumococcal vaccine. The overall 30-day mortality was 20.2% with CAP, and 31.7% among patients with pneumococcal pneumonia.

CONCLUSION

Serotype 7F, covered by all pneumococcal vaccines, was the most common serotype. The high 30-day all-cause mortality highlights the substantial burden of CAP in cancer patients. Enhanced serotype surveillance and vaccine-effectiveness studies are warranted.