How effective is S-1 maintenance chemotherapy for patients with advanced non-small cell lung cancer?

This study examined how effective S-1 (Teysuno) chemotherapy is for patients with advanced non-small cell lung cancer (NSCLC) following initial chemotherapy treatment. The results showed that S-1 improved patients’ survival without NSCLC worsening but increased the number of side effects.

Treatment for patients with advanced (stage III or IV) NSCLC often proceeds in phases. The first phase is initial chemotherapy (induction). This is followed by lower doses of chemotherapy to keep the cancer at bay (maintenance therapy). 

Carboplatin (Paraplatin) is often used for induction chemotherapy. It was recently shown that S-1 chemotherapy improves treatment results. S-1 includes  tegafur, gimeracil, and oteracil. As S-1 is a tablet with fewer side effects than other chemotherapies, it might be useful as maintenance therapy.

131 patients with advanced NSCLC were included in this study. Patients received carboplatin and S-1 induction chemotherapy. After this, the patients were divided into two groups. 67 patients received S-1 combined with another therapy of their clinician’s choice (CC) for maintenance therapy, while 64 patients received CC alone.

Patients in the S-1 plus CC group had a 45.2% higher chance of surviving without NSCLC becoming worse than patients in the CC alone group. Patients survived an average of 1.6 months before NSCLC became worse with S-1 plus CC and 1 month with CC alone.

S-1 did not change patients’ chances of survival overall. Patients in the S-1 plus CC group survived an average of 16.7 months and patients in the CC alone group survived 17.8 months.

S-1 increased the number of side effects patients experienced. The most common side effects experienced by patients in the S-1 plus CC group were lack of appetite (21.9%) and fatigue (20.3%). 82.8% of patients in the S-1 plus CC group had low red blood cells compared to 56.3% in the CC alone group.

The authors concluded that S-1 improved maintenance therapy results for patients but increased the number of side effects.

The manufacturer of S-1, Taiho, funded this study. Patients received different maintenance therapies from their clinician which makes comparisons between the groups difficult. This study would benefit from including more patients.