What a pre-treatment risk score adds to doctors’ judgment in older adults with lung cancer

What is it about?

Treating lung cancer in older adults means weighing the benefit of treatment against its side effects. In practice, doctors adjust the drugs and the starting dose according to their own impression of how fit a patient is. The Cancer and Aging Research Group (CARG) score is a tool designed to predict chemotherapy side effects in older adults. It combines age, details of the treatment, and routine blood tests with simple questions about health and daily life. These include recent falls, difficulty walking one block, needing help to take medicines, and hearing. At one hospital in Japan, we calculated this score before treatment in patients aged 65 or older who were starting anticancer treatment for lung cancer. The score was not shared with their doctors, who chose drugs and doses as usual. In the 75 patients we analyzed, we compared the 18 with a high score (8 or more) with the other 57. We looked at how doctors set the starting dose and which side effects occurred. We also checked whether patients received at least 70% of the standard dose over the first four treatment cycles. Doctors planned a lower starting dose less often for patients with a high score (3 of 18) than for the others (37 of 57). In the first cycle, patients with a high score more often had moderate or more severe side effects not related to blood counts (10 of 18 vs. 15 of 57). The extra side effects were mainly nausea, constipation, low sodium or potassium, and a rise in creatinine. Side effects on blood counts were similar (9 of 18 vs. 30 of 57). Fewer patients with a high score reached 70% of the standard dose (3 of 18 vs. 22 of 57), but this difference was not statistically significant on its own. It became significant once planned dose reductions, age, and stage were taken into account. Among patients who started at the full dose, 3 of 15 with a high score reached this level, compared with 13 of 20 with a lower score.

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Photo by Vitaly Gariev on Unsplash

Photo by Vitaly Gariev on Unsplash

Why is it important?

Doctors already adjust treatment for older patients based on their own impression. The open question is whether a structured score adds anything to that judgment. Because the score was kept from the treating doctors, this study could examine that question without the score influencing their decisions. Geriatric assessment is recommended in Japan but is not widely used, so the question matters in everyday practice. The extra risk in patients with a high score did not appear as low blood counts. It appeared as nausea, constipation, and changes in blood salts and kidney tests. Supportive care can address these problems, for example with anti-nausea and bowel medicines and with checking blood salts and kidney function from the first cycle. A high score may therefore be most useful as a signal to plan extra support from the first cycle, alongside the doctor’s own caution. Whether such support improves how well patients tolerate treatment still needs to be tested. The study has several limitations. It was small, with 18 patients in the high-score group, and it was carried out at one hospital. Of the 102 patients enrolled, 27 did not complete the four-cycle evaluation period for reasons other than side effects, mainly cancer progression or a decline in their condition. They were not analyzed, although their CARG scores were similar to those of the analyzed patients. Many comparisons were made without adjusting for multiple testing, and some analyses were added after the data were collected. The link with dose intensity was not seen when the score was analyzed as a continuous number. Survival could not be assessed reliably, with only 19 deaths. These findings need confirmation in larger studies.

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