I hypothesise that ALL effective hair loss treatments are potentially carcinogenic in vulnerable individuals. Literally ALL of the factors which are being upregulated to result in HAIR GROWTH, are also factors which are all upregulated in CANCER.
Think about it, Chemotherapy often results in hair loss. Why is this? It is because it is doing the exact opposite to what Hair growth treatments are doing. For hair growth to occur there has to be complex release of various substances, and cell proliferation. On a simplistic level (and there is sooo much more to it), cell proliferation is going to increase the chance of carcinogenic cells developing. Chemotherapy causes CELL SENESCENCE (cell death) which is why the hair falls out. To cause cell senescence various substances, growth factors, etc have to be DOWN REGULATED. These are the very same substances which are UPREGULATED in hair treatments.
eg. Minoxidil: Minoxidil is a potassium (K+) channel opener. The opening of K+ channels causes cell proliferation. Role of Voltage-gated Potassium Channels in Cancer
Laser Helmet – works by opening K+ channels. Spiro is especially lethal – Oestrogen agonist in breast. Tumours in rats. Upregulation of ALL the factors linked with cancer and what helps it proliferate, eg VEGF, EGF, FGF, MMP, and on and on.
Activation of SRC Tyrosine Kinase — From wiki: Tyrosine kinases add phosphate groups to the amino acid tyrosine in the target protein. They can cause cancer by turning the receptor permanently on (constitutively), even without signals from outside the cell. And specifically SRC Tyrosine Kinase.
What are your thoughts on the cancer – artificially induced hair growth link?
Life has its risks. Do you know how much radiation you get when you fly across the country in a commercial aircraft (see here)? Regular flights may increase the risks of a variety of cancers, but if your quality of life means that to bond with your family you must fly to the other coast, would you rather stay safe and lock yourself in the basement where the radiation levels are much safer?
We all have decisions in life, and with regard to hair, the various treatments available to prevent or reverse hair loss have not been shown to be carcinogenic. It’s your choice!
I always worry when a single case is put forth as a typical example of a problem. I do not doubt this young man could’ve seen some side effects, but I would think that this is a very rare example if it is true. I do doubt the long term impotence reported, however. Propecia has a half life of 4-5 hours, which means it is out of the blood stream in a day. Tissue fixation of the drug may last for up to a week, but by then, all of the effects of the drug should be gone. Unfortunately, the report gives us little insights into objective evidence for the ED that doctors would explore, such as nocturnal penile tumescence studies, to substantiate if the problem is real or psychological.
I was flipping through the current Nov/Dec issue of the Hair Transplant Forum International (a print newsletter for the hair transplant industry) and wanted to share something I read. 
I am aware of Latisse (bimatoprost), which is currently FDA approved for growing eyelashes, and I’ve seen one patient who took it upon himself to try it on the scalp with no success. The dose is quite small for eyelashes and it’s quite expensive for treating the scalp, and I’m not sure what dose would even be necessary for the scalp.