Hodgkins Lymphoma treatment during pregnancy and breastfeeding

[MarenAnne]

When I was 18 weeks pregnant I was diagnosed with Hodgkins Lymphoma with Bulky Disease (a mass of 7+ centimeters was found in the mediastinum of my chest). I began chemotherapy treatment at 20 weeks and received 2.5 cycles (5 sessions) of ABVD chemo. The drugs used in ABVD are Adriamycin, Bleomyecin, Vinablastine, and Doxorubicin. I was also given Dexamethazone, which I had an allergic reaction to, as well as antiemetics, pain relievers, and other steroids. My treatment was interrupted by getting pneumocystis pneumonia, which I was hospitalized for and given numerous antibiotics and antifungals including Zosyn, Zithromax, and amoxicillin. There was not time before delivering the baby to have more chemo, so my treatment was paused.
I delivered my baby at 38 weeks and have been nursing her. She is now six weeks old. I have to resume treatment in a week and do 1.5 cycles (3 sessions, 6 weeks) of ABVD chemo, and then radiation. I would like to pump and dump my milk through the chemotherapy so that i may breastfeed my daughter afterwards. However, I am reading mixed information on exactly how long I should withhold and pump and dump after my last chemo treatment. I have seen the half life of two of my ABVD drugs are up to 48 hours, so it’s advised that I discard the milk for two weeks after my last treatment. But, by my calculations trace amounts would still be in my milk according to the half-life math. Can infant risk please advise? Is there any way to test my milk after the two weeks post-treatment in order to insure the milk is safe?
Thank you in advance. I plan to update this thread with my experience of what happens. I intend on pumping and dumping through chemotherapy, and expect a dip in my supply as I have read others experienced that. I hope to get through that and possibly support my supply with galactagogues after I am cleared to nurse again.

[Brian W]

I saw somewhere else on the forum that one should wait 7 half lives, which, for doxorubicin, is something like 2 weeks, but I would like to know the basis for that. 7 half lives would still yield 7/10ths of a percent, so I wonder why that is deemed an acceptable level.

[kaytlin]

Hello! Apologies that we haven't had a chance to respond to MarenAnne's question. For more immediate help, call the InfantRisk Center and the nurses will look up each of your meds and help find which drug is the riskiest (usually the longest half life) and give you pointers.

I can help now with your question about half-lives and residual drug. We use half-life calculations to roughly estimate how much of a drug is left in your body, and would be available to pass into your milk. A half-life is the amount of time it takes for half of the drug to be gone. So at one half life you have 50% of the drug remaining, 2 half lives 25% remains (half of the 50%), and so on. 7 half lives leaves 0.78% of the dose and 10 half lives gets you down to 0.1%. The more half-lives you wait, the closer the % remaining gets to zero...but the calculations will only ever approach zero--it will never calculate to zero. So at 20 half-lives, there is 0.0001% remaining which is really not useful. In real life, at some point, there isn't any drug left. With chemo, you usually see recommendations to wait 7 or 10 half lives to return to breastfeeding. These recommendations are a practical approach to decide when the drug is effectively gone (and no longer a risk).

To determine infant risk when assessing breastfeeding safety with medication use, there are some more things to know. The body usually does a fantastic job of regulating what is present in breast milk. There is a "barrier" similar to the blood-brain barrier that separates the milk compartment from mom's body. Maternal medications that are small molecules (like some of these chemo drugs) are usually present in milk at around the same concentration as what is in mom's blood...which will give baby a MUCH lower dose than what mom had. The baby-sized "dose" of medication when breastfeeding is continued is almost always less than 5% of what a full baby-sized dose would be if you needed to directly dose them. So if you're waiting 7-10 half-lives for the drug to mostly be gone in mom's blood, then baby's dose really is going to be nothing. That's exactly what we want.

I don't there is any testing available in milk for your drug regimen. Even if it existed, you would be unlikely to get the results back in time to help you make a decision.

On another note, we do have moms that return to breastfeeding after chemo--they find it very fulfilling when it is successful. You're right in your research that they have a hard time with milk supply. Please be kind to yourself, and do the best that you can! Remember, exclusive breastfeeding is more metabolically demanding than pregnancy.

I hope this helps.

Dr. Krutsch