Immunotherapy

I recently turned on television news. They were presenting medical information. The big news was that immunotherapy for cancer was allowing patients to not need surgery or chemotherapy. Some patients were actually cured by immunotherapy alone.

Whenever I hear a headline like that, I know there is usually more to the story. So I looked up the original article that they were discussing. It was published in the New England Journal of Medicine on April 25, 2025.

The original article almost told the same story. However, it was not anywhere as earth shaking as the television news would have you think.

The first issue is that it only involved a total of 117 patients. Only 103 patients actually completed the course of therapy. This is good for an initial study. However, with so few patients the results are difficult to generalize.

The second issue is that it only involved two types of cancer. One group was rectal cancer. There were 49 patients in this group. The second group had what are called non-rectal solid tumors. Thee were 54 patients in this group. Those groups were chosen because the usual approach is surgery to remove the tumor mass.

The third issue is that it was aimed at locally advanced cancer without metastases. Patients were all Stage I, II or III.

The fourth issue is that the type of tumor was called deficient mismatch repair (dMMR). dMMR is a biological system that corrects errors in DNA production. These forms of cancers have a problem with that system so there are many DNA abnormalities. Because of that, the immune system can normally react to the abnormalities. Thus immunotherapy is more likely to be useful in these cases.

Of the 49 patients in the rectal cancer group, all completed the therapy. However, only 37 of the 49 remained cancer free for the 12 month period required to consider the treatment effective.

Of the 54 patients with non-rectal solid tumors, 35 patients were considered to have a clinical response at 12 months.

Overall 82 of the patients were able to avoid surgery. That would have been the standard approach in the past.

Cancer immunotherapy research is one of the areas affected by cuts to NIH funding. It is not clear what affect this might have on future research in this area.

The bottom line is that the study addresses specific types of cancer. It looks at those having problems with DNA repair. And they only looked at 117 patients (with only 103 completing the entire course of therapy)

Thus while the results are promising, the article did have a conclusion. It read: “Whether this approach can be extended to all early-stage dMMR solid tumors regardless of tumor site, is unknown”. Television news appears to have the answer that the researchers do not.