Does chemotherapy make cancer worse?

Question

Several sources, among them Huffington Post and Daily Mail claim a recent study showed that chemotherapy, which is used as a cancer cure, actually makes cancer worse.

Chemotherapy can backfire by helping healthy body cells to fuel treatment-resistant cancer and growth, research has shown.

The surprise discovery suggests that many forms of cancer treatment can actually make the disease tougher to tackle.

[Daily Mail and Huffington Post both published the same, word for word, and neither acknowledges the other as source. But that’s just an aside.]

This sounds like very bad news indeed. Is there any truth to it?

Answer 1

No.

This result is a blatant misrepresentation of what the study¹ actually did, namely cataloguing changes in behaviour in the cells surrounding a tumour when exposed to anticancer treatment, and how those changes affect the resistance of the tumour to the treatment.

Cancer Research UK calls the headlines “misleading” and warns not to take them seriously. They go on to say that,

In fact, the research from US scientists that sparked the coverage categorically does not show chemotherapy makes cancer harder to beat. Instead, the work gives scientists a vital insight into one way that the body can develop resistance to chemotherapy, and it could help explain why treatment sometimes stops working.

And quite contrary to what the newspapers write, they say that “this is a ‘good news’ story”, because it explains a known weakness of existing chemotherapy which can help develop better treatments.

They also clarify that the new research “doesn’t affect current treatment”.

Cancer patients do not need to be alarmed by today’s headlines and should not stop treatment. Decades of clinical trials have proved the effectiveness of chemotherapy in treating cancer and extending life …

Radiotherapy and surgery – not to mention other strategies like healthy living, early diagnosis and screening – are crucial, but chemotherapy plays a big part too. And work to improve it must be welcomed.

But while we applaud the media’s interest in this important scientific paper, we want to calm the nerves of anyone worried by some of the headlines, which by themselves don’t paint an accurate picture of the research.

Sloppy news coverage indeed. Cancer Research UK call out this sloppy coverage again by nothing that

Contrary to what some news outlets claim, this is not a particularly surprising finding either.

In fact, the acquisition of resistance to anticancer treatment by tumours is a very well-known and unfortunate side-effect. For a newspaper to claim that this is a “surprising” new finding is nothing short of ignorant.

References

1. Y. Sun, J. Campisi & al., Treatment-induced damage to the tumor microenvironment promotes prostate cancer therapy resistance through WNT16B, Nature medicine (2012)

Answer 2

No - but it often causes cancer. Not immediately, but years down the road.

Alkylating Agents as Environmental Carcinogen and Chemotherapy Agents

Alkylating agents are an important class of carcinogens. [...] On the other hand, alkylating agents are used in certain chemotherapy regimens

Pathology of Therapy-Related Myeloid Neoplasms

Therapy-related myeloid neoplasms(t-MN) are a heterogeneous group of clonal hematopoietic stem cell disorders that are directly related to previous cytotoxic chemotherapy and/or radiation therapy.