According to Cancer.net
“People who have been exposed to radiation or to asbestos, benzene, pesticides, and other chemicals used in rubber manufacturing may be at higher risk for developing myeloma. People often exposed to wood products, such as carpenters, furniture makers, and paper makers, are also at higher risk”
This suggests that there may well be a correlation between your husband’s diagnosis & that of his colleague. However this may be impossible to prove. I know two immediate next door neighbours who were both diagnosed with myeloma,& have heard of a husband and wife who both have the disease and of 7 myeloma patients who use the same GP surgery. These all suggest possible environmental issues at play. But myeloma is still rare, for instance most wood workers will not develop it.
As your husband and his colleague may not be being treated at the same hospital, let alone by the same doctors, it is worth telling your husband’s consultant about his colleague’s diagnosis. At the moment we have no national database to record this type of information but hopefully overtime additional pieces of the jigsaw puzzle that is myeloma will become apparent.
It’s believed that myeloma results from multiple mutations over time, we must all have a number of specific causes or causal events. But once we have myeloma, I feel that the cat is out of the bag, and knowledge about how we developed the disease is less important than identifying successful ways to keep it inactive (or find a cure).
I try not to worry for my children as their father has MGUS and I have myeloma- were we all exposed to something carcinogenic? Instead I concentrate on things I can do something about. But you will have to make your own decision.