On the value of carbon-ion therapy

Kudos to Robert Schulz and A. Robert Kagan for raising the issue of the costs and benefits of proton therapy and other forms of charged-particle radiotherapy. The topic continues to be an important one, particularly in view of the recent national political attention given to affordable health care.

As they indicate, the best way to prove efficacy of a treatment modality is to conduct a randomized controlled trial. But such trials are costly, in part because cancer can take years to develop. In lieu of those data, retrospective studies can give an indication of the promise of a clinical intervention. A recent review in Lancet Oncology points to a potential benefit of proton radiotherapy over conventional radiotherapy for the relatively rare cases of paranasal sinus and nasal cavity malignancies. ¹

Toward the end of their letter, Schulz and Kagan state that “about 90%” of cancer mortality is caused by metastases and that in such instances radiation is used primarily to render palliative care to the patient; it is not curative. Although cancer mortality is due primarily to metastatic disease, ² cases ending in mortality constitute a minority of all cancer diagnoses. To focus only on those cases is misleading and pessimistic. The five-year survival rate for all cancer diagnoses ³ is 64%. In the majority of cancer diagnoses, the patient goes on to live a cancer-free, or cancer-controlled, ⁴ life for at least five years, and radiation, including proton-beam therapy, often plays a crucial role in the outcome.

The discussion of what society is willing to pay to treat its cancer patients is a needed one. However, to focus only on the terminal, metastatic cases misses the big picture of how the disease is currently diagnosed and treated.