Food cravings and cancer?

I read this article back in August and have been meaning to follow up on it.  Sadly, I haven't had time yet, but I thought I'd put it out there anyway.

In short, a woman craved lettuce (upwards of four heads a day) and her husband (a scientist) worked out that she might be eating so much lettuce to make up for a nutrient that is commonly lost in breast cancer patients.  Turns out, he was right.  His wife did have early breast cancer, she was treated, and is now doing very well!

LINK: http://www.dailymail.co.uk/health/article-2021027/Breast-cancer-symptoms-Elsie-Campbell-diagnosed-develops-LETTUCE-addiction.html