A few weeks ago, many major news outlets reported this news, sensationally titled "cancer disappeared!".
The news was based on a report on New England Journal of Medicine (NEJM), published on 6/5/2022. The journal is highly regarded.
Link to the paper. https://www.nejm.org/doi/10.1056/NEJMoa2201445
We picked up the paper for our journal club in the lab.
Background.
(a) Immunotherapy reagent (PD1 blocker) has shown success in various cancers, including metastatic (stage 4) colorectal cancer.
(b) PD1 blocker indicated particularly good efficacy on a subset of cancers with mismatch-repair deficient characteristic.
(c) Standard colorectal cancer therapy is initial treatment with chemotherapy drugs (combination of DNA damaging drugs such as fluoropyrimidine and platinum compound oxaliplatin), followed by chemoradio therapy then surgery.
(d) But the response rate for the standard therapy is up to 25%. The current therapy comes with complications, toxicity and fertility challenge. Much to be desired.
In the report, the group in Sloan Kettering Memorial Cancer Center hypothesized that single reagent PD1 blocker could be effective in patients with mismatch-repair deficient, localized (stage 2 and 3) rectal cancers.
They enrolled 16 patients with mismatch repair-deficient rectal cancer and stated treatment with PD1 blocker every 3 weeks for 6 months.
In the planning, (Plan A) if the single drug treatment work, no chemo or surgery, and (Plan B) the PD1 blocker treatment should be followed by chemoradiotherapy then surgery (=standard therapy).
They monitored the cancer at the start, 6 weeks, 3 months and 6 months.
Amazingly, the cancer literally "disappeared" in 100% of 12 patients who went through the 6 months treatment of PD1 blocker.
In all clinical monitoring parameters (imaging analyses with MRI, PET, endoscopy, digital examination, histopathological analyses on biopsy samples), rectal cancers were not seen. They did not even have to pull out the Plan B/follow up with chemoradio therapy then surgery.
If we point out something cautionary and less rosy,
(i) mismatch repair-deficient colorectal cancers are about 5-10% of colorectal cancers.
(ii) This is a phase2 trial with small size of white patients in single institute.
(iii) If the cancer ever comes back or not in a long term remains to be seen.
(iv) They did not talk about the cost, but PD1 blockers are not cheap.
Yet, the way cancer disappeared with only mild to moderate side effects if any was indeed newsworthy.
Cancer is a collection of many diseases. They reported a very effective way to deal with mismatch repair-deficient, stage 2/3 rectal cancers. Highly promising.
Cancer is "cured" like this. You can call it a trench warfare. By conquering one type of cancer at a time, we'd eventually have effective ways to "cure" many other types of cancers.
[Figure 1A from the paper. An example of "cancer disappearance" over time]
