Wednesday, April 17, 2013

April is National Oral Cancer Awareness Month

According to SEER, it is estimated that 40,250 Americans (28,540 men and 11,710 women) will be diagnosed with oral and pharyngeal (throat) cancer in 2012. It will kill roughly one person every hour in America (7,850 Americans) this year. Oral cancer kills more people than endometrial, renal, melanoma, and thyroid cancers do; all of which are considered "common cancers." [source] Where oral cancer is located and at what stage it is at when diagnosed have a huge impact on the survival rate. Lip cancer at stage 1 is 96 percent, but tonsil cancer at stage 1 is 56 percent.

We all know that stuff or kind of recall it when we see it. But there are two things that are often reported as facts, which have always bothered me.

1. Oral cancer is strongly correlated to HPV. That’s only partially true. HPV is only strongly correlated to posterior cancers like oropharyngeal and tonsil. I think a lot of dentists believe all oral cancers are increased due to HPV, but that is not the case.

2. The other thing that bothers me is how is the 5-year survival rate for oral cancer is 57 percent if only 8,000 a year die and 40,000 a year get it? If you use the 8,000 and 40,000 figures, the survival rate should be closer to 80 percent. However, “5-year survival rate” simply means “chances of being alive in five years,” NOT that the cancer kills those people. So, the 5-year survival rate of any group of people is not 100 percent. The older the average age of diagnosis, the lower the survival rate will be just because of the older age. But that still doesn’t explain the difference between 80 percent and 50 percent. The median age at diagnosis for cancer of the oral cavity and pharynx is 62 and the average is right around 60. Let’s just use 62 as the starting point. According to Social Security, about 93 percent of 62-year-olds will survive to age 67.[source] But, on average, only about 80 percent of people with oral cancer will survive those five years. That’s when you do not include those directly killed by cancer. That’s a big difference; so either I’m mistaken or misinterpreting something or those with cancer die from other things at an incredibly higher rate than their peers (3x in this example). Which is it?

Bryan Bauer, DDS, FAGD

1 comment:

gatordmd said...

Bryan,

I have never thought of the survival rate this way.
So I guess there is a 5 year survival rate for people without cancer. So you are saying that the 5 year survival rate for a 60 year old without cancer is something like 80%.
Meaning 20% of 60 year olds are going to die anyway in 5 years decreasing the 5 years survival rate of all cancers.

Interesting.
Thanks
john

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