The short answer is yes. There is an increased risk of secondary cancers when you have an MPN, including breast cancer. The reasons for this are complex and likely multifaceted. I do not see this is something to worry about. I see it as something we should do something about. We should all be sure to follow routine monitoring protocols. We should reduce our exposures to carcinogens, toxins, and contaminants in the foodstream. We can take action to reduce our risks.

Here is some information on MPNs and secondary cancers. There is more available if you want to pursue it.

https://ashpublications.org/blood/article/135/5...

https://ashpublications.org/ashclinicalnews/new...

https://ascopubs.org/doi/abs/10.1200/JCO.2018.3...

I agree with Tia 100%. Nice summary of the articles BTW. It is very complicated, nuanced and multifaceted. I expect that some of the same things that can be a trigger for the MPN mutations and for them turning into a disease state are the same things that trigger other cancers. I also agree that it is not worth worrying about things we can't control. In my own case, I also have Neurofibromatosis Type 1. The NF1 also increases my risk of other neoplasms. The NF1 is also a non-driver mutation that increases my risk of MPN progression to some undefined degree. Despite that, I still do not lose any sleep over whatever level of increased risk there is in my situation. Rather than worry, I just try to be proactive in managing my health and avoid exposing myself to things that could increase my risks. That is just prudent for anyone regardless of whether you have a MPN. .

Dear JennyLynn and Steve,

Exploring a bit more studies on the topic (link between MPNs and other cancers), I noticed some more methodological issues. For example, I can notice bias in selecting both cases and controls. This means that there was not an exact case-by-control match, but rather the authors ensured a match between cases and controls via enlarging the control group until the means & distribution for age & several other factors were similar. This introduces plenty of bias.
Also, from study to study, there are significant differences in which cancers are associated with MPNs. Sometimes what is significantly associated in one study is not in another one. This means that these results are sample dependent. As studies do not always take into account a host of other factors that are known to increase risk for cancer, we cannot reject the hypothesis that the association between MPNs and others cancers is due to other independent factors the authors did not include in their study.
Also, while some cancers are more likely to be caused by environmental factors (e.g., lung cancers, skin cancers), not all of them are, and thinking that we can control our risk for developing cancer, especially when that cancer is less likely to be caused by environmental factors can do us more harm than good.
Not smoking, not drinking excessively, eating a balanced diet, using sunscreen, going for screening, knowing family history or potential professional risk that can inform a more frequent screening, being as active as the body allows us, all these are good strategies.
But we cannot individually control outdoor pollution of any kind, or our genetics. We also need to accept that many factors are out of our control. Ironically, ecological eggs in several regions in EU had high levels of PFAS/PFOAS. The more we try to control some risks that are beyond our control, the more likely we will accidentally expose ourselves to other risks, because some things will always be out of our control.

So some awareness, but also some acceptance is a good strategy if we are to pass through this without waves of more worries and guilt.

Many hugs of support,
Tatiana

Thank you again

Dear JennyLynn,

💔
That is a lot to have to deal with.
Sending you plenty of solidarity.

My dad was also diagnosed with breast cancer, in his case at age 46. He was having undiagnosed ET at the time. The high number of thrombocytes made the GP think of cancer and they detected the breast tumour, but ignored the MPN. In his case, the breast cancer was, most likely, due to work exposure. The ET was, most likely, inherited. His mom also had issues with thrombocytes all her life, albeit only slightly above the upper limit.

I wish you all the strength and support you need to pass through this.

Know that you can write to me at any time here if you want to talk to someone.

Many hugs of support,
Tatiana