Pleural effusion confusion...

My therapist thinks I use learning about the science and medicine of MBC as a coping mechanism. She isn't wrong. But also, there are far worse out there. Here I'm going to do a little writing about malignant pleural effusions- what are they, how do they happen, and how do we treat them, at least in the context of MBC. 

I was diagnosed with a pleural effusion in 2020. I had no idea what one was or that breast cancer could cause this. 

Cancer Research UK / Wikimedia Commons

So what is it? A pleural effusion occurs when fluid builds up between the outside lining of the lung (pleura) and the lining of the chest wall (pleura). The space between these two linings is called the pleural space and usually has about 10-20 ml ml of fluid lubricating the area so when your lung expands and contracts it can do so easily (that's my understanding anyways). However, various disease states can lead to a build up of this fluid to 100s of mls to over a liter. This puts pressure on the lung and can cause shortness of breath.

Pleural effusions can be caused by heart or lung problems, but when they're caused by cancer they're known as "malignant pleural effusions". Most are caused by lung cancers, but the second most common cause is breast cancer, where 23% of MBC patients develop a pleural effusion over the course of the disease. So, why do these form? There are two ways that a buildup of fluid in the pleural space can occur- increased production of fluid, decreased drainage of fluid, or both. Decreased drainage can occur due to cancer cells/tumors clogging the vessels that drain fluid from tissues (lymphatic vessels). However, there are several mechanisms by which fluid can build up. For a review check out this 2023 paper.

Because pleural effusions can cause shortness of breath (dyspnea), coughing and sometimes pain, they are...a pain and definitely affect quality of life. There are various methods for dealing with them, and I've had experience with four. 

https://www.physio-pedia.com/Thoracentesis

First, is a short term fix- the thoracentesis. This is an out patient procedure where they slip a needle then tube into the pleural space and draw out the fluid. It's quick, but not my favorite thing, I think largely because the bottom part of my lung is "trapped" meaning it can't expand (due to long term compression?). Over-draining therefore causes pain, and it's tough to get the doc to stop sometimes. But it is quick relief and a stop gap measure for longer term treatment.

The next is placement of a PleurX catheter - a tube that is run into the pleural space with about 6 inches left outside to drain the lung at home. Bonus here is you don't have to go to the hospital and you have total control of how much and how fast you drain. You do need someone to help you, but home health (should) be available if there is no one at home or who can come help you. Down side- no swimming or baths and aesthetically you can see the bandaged area through shirts. Even though the covering is water proof it can't stand up to too much pressure and you don't want any bacteria in there. 

A permanent fix is the pleurodesis, but it is also by far the most invasive. A chemical pleurodesis is when a surgeon goes in using a chemical (usually talc) to "glue" the pleura together. If the pleura are stuck together, fluid simply can't build up and put pressure on the lung. The process requires a hospital stay as a chest tube with vacuum is inserted after the talc in order to continuously drain the area, which will then stick together due to the inflammation caused by the talc. It's not the most comfortable thing but seems to have worked (minus the previously mentioned trapped lung part, but luckily it's small enough that only a small amount of fluid can build up). 

And then there's treating the cancer itself, which is what led to resolution of my first pleural effusion after four months with a catheter. Any drug that works to stop cancer growth should help stop the effusion. Here's hoping this next drug works too!

Finally, don't google life expectancy. I was diagnosed metastatic with a pleural effusion and am here over three years later. And I plan on being here for a bit longer still. 

Happy to answer any questions about my experiences with my least favorite cancer symptom (as of now haha).  Feel free to reach out at beumerae@gmail.com or you can find me on Twitter @amybeumer