Chemotherapy drugs sometimes have vicious side-effects. Adriamycin (also called doxorubicin) can cause heart damage. Adriamycin is part of the R-CHOP treatment that all non-Hodgkin lymphoma patients get. A characteristic of Adriamycin is that the heart damage can manifest months or years after the end of treatment. I have to stay vigilant to identify any problems with my heart.
What are the chances that my heart will become damaged? Happily, they are not very high. I’m almost three years post treatment and my heart is ticking along fine.
There is another reason why I am optimistic. The dose of Adriamycin that I received was less than most non-Hodgkin lymphoma patients get. Here’s why:
I was set to get six courses of R-CHOP. After the fourth course I was in a bad way. I collapsed one day and my red blood cells were so low that the doctors were considering a transfusion. I found some studies that concluded three courses of treatment were sufficient for patients like me. I discussed these with Dr. Fisher and he said we could terminate the R-CHOP. If you want to see a complete discussion of this sequence go here Babysitter. Collapse. Aftermath. Computer. Visits. Card. then here Milestone; Going forward; Visits; Beard.
So I got less Adriamycin than other patients, but how much less? And how close was I to getting a dangerous dose? To get a full understanding of this, it’s necessary to run the numbers.
Doses of many drugs are prescribed on the basis of milligrams per square meter of skin surface (mg/sm). Based on my height and weight I have 1.77 sm of skin. The formula is: skin surface in meters squared is
the square root of (height x weight / 3131)
where height and weight are inches and pounds respectively.
If you look in my R-CHOP drug logs (here, here, and here) you will see that I had 87 mg of doxorubicin (Adriamycin) each time. Dividing this by my skin area (1.77 sm) shows that I had 49 mg/sm each time, or 196 mg/sm over the four courses.
According to Wikipedia, “When the cumulative dose of doxorubicin reaches 550 mg/sm, the risks of developing cardiac side effects, including CHF, dilated cardiomyopathy, and death, dramatically increase.” Thus, at 196 mg/sm, I am well below the level of maximum danger.
So mathematical analysis says that my risk of heart problems is low. But what about the real world? How is my heart function when I exert myself?
In 2010 I entered the Mt. Washington Road Race. You can read about it in the epilogue to my e-mails. On June 16, 2012 I participated in the race again. I had spent five months training for it. I was up to three hours on the treadmill at 2.8 mph and 12% elevation.
The training is brutal and the race even more so. The elevation gain is 4,650′ in a distance of 7.6 miles. During the race my heart beat at 75% or 80% of its maximal rate for almost three hours. If my heart can do that, I have to conclude that it is healthy.
So my health seems to be good. This was confirmed on 8/14/12 when I saw Dr. Weckstein for my scheduled checkup.
But it was not all joy and celebration. I still have prostate cancer and Dr. Weckstein wants to do a prostate biopsy next year. Cancer is the house guest you just can’t get rid of.
Postscript:
The acronym “CHOP” can be confusing. It stands for four drugs used to treat non-Hodgkin lymphoma. Yet Adriamycin and doxorubicin don’t seem to be in the list. The problem is that the same drug can have multiple names. Here’s a Wikipedia entry (slightly modified) that resolves this confusion:
Cyclophosphamide (Cytoxan), an alkylating agent which damages DNA by binding to it and causing cross-links.
Hydroxydaunorubicin (also called doxorubicin or Adriamycin), an intercalating agent which damages DNA by inserting itself between DNA bases.
Oncovin (vincristine), which prevents cells from duplicating by binding to the protein tubulin.
Prednisone or prednisolone, which are corticosteroids.