Should I use a plural noun when grouping two cancers? “Pancreatic and prostate cancer(s)”

My girlfriend (non-native speaker) recently approached me with the following question - which of the following would you use?

• Glycemic variants affect pancreatic and prostate cancer, but not colorectal and breast cancer.

• Glycemic variants affect pancreatic and prostate cancers, but not colorectal and breast cancers.

As a native speaker I felt like both were appropriate - in the first, you're implying the missing 'cancer' after pancreatic - the expanded form would be "pancreatic cancer and prostate cancer".

In the second, you're grouping them together and saying (pancreatic and prostate) cancers.

Does this analysis make sense? Which of the two would be a preferred or more common usage? The context is academic writing, if that makes a difference.

Solution 1:

The dictionary confirms that cancer has a plural, cancers. It also confirms that cancer is a variable noun, so it can be countable or uncountable.

As cancers grow, a cancer is singular no matter how large it is or how far it spreads. Clinicans refer to multiple cancer sites when someone has different kinds of cancers, but everyday speech you might say someone has multiple cancers.

However, your example is a little different, and functions like a list:

Glycemic variants affect pancreatic and prostate cancer, but not colorectal and breast cancer.

When you make a list of multiple types of something, you can end on a singular noun, for example:

We sell strawberry, chocolate, and vanilla ice-cream.

This is essentially the same as saying:

We sell strawberry ice-cream, chocolate ice-cream, and vanilla ice-cream.

You could pluralise 'ice-creams' if you wanted to refer to each one sold, but ice-cream can be a uncountable noun so it works either way.

Likewise, your example is fine as it is - you could say "pancreatic cancer and prostate cancer", so you can also say "pancreatic and prostate cancer". Or "cancers", either is fine.