Five-year follow-up study of saliva, mutans streptococci, lactobacilli and yeast counts in lymphoma patients

Abstract

Twenty-two patients out of the 79 that were originally included were examined 5 years after beginning anticancer therapy for lymphomas. The patients' cumulative data on salivary flow rate, buffering capacity and acidogenic microbial counts were compared with respective data of 17 patients who died during the follow-up. Stimulated saliva samples had been taken at baseline and during the cytostatic treatment with combination chemotherapy, and 1 year and 5 years later. Chair-side kits were used at the hospital ward for the assessment of the study parameters. Mean saliva flow at baseline was 1.5 +/- 0.7 ml/min in the surviving group and 1.5 +/- 0.8 ml/min in the deceased. Salivary flow rates were not affected by the anticancer treatment and there was no statistically significant difference between the groups in this respect. A significant difference was observed between the groups in salivary buffering capacity values at baseline: only 32% of the survived had low buffering capacity in comparison to 69% of those who later died (P < 0.02). Buffering capacity values remained low in 50% of the surviving patients 5 years later. Higher mutans streptococci and lactobacilli counts were seen among the deceased than in the survived patients but mutans streptococci decreased significantly in both groups after the start of the anticancer therapy (P < 0.05). The number of positive yeast counts increased consistently during the chemotherapy in both groups, being higher in the survived when compared with the deceased patients. Yeast counts remained positive 5 years later in 73% of the survived patients, while the mean mutans streptococci and lactobacilli counts decreased below baseline values. The results showed that persistently high salivary microbial counts and low buffering capacity may be linked with poor prognosis.