Question about IBC BC statistics
I've been trying to find the answer to this via journal data, but no luck.
Inflammatory breast cancer is cited as "very rare" and that "1-5%" chance of IBC.
However, most women with IBC seem to be diagnosed once the IBC has caused the 'typical symptoms', many of these symptoms seem to imply that the BC had been in the breast causing "less obvious" symptoms for a while.
And, it sounds like many women struggle for months to get an answer for their symptoms before diagnosis.
So, given these pieces of information, my question is:
What population does the 1-5% statistic represent?
- Does it represent the population of "all people in the US with Breasts"? (ie: the total alive population; this seems unlikely)
- Or, does 1-5% mean "anyone who presents at any doctor with any breast symptom or concern to include the things women get brushed off for frequently before ultimate diagnosis: itchy breast, bug bite, allergy, eczema, psoriasis.
- Or, is it representing of all dx cancer cases? In this case, it is of "known cancers" which relies too much on the ability to diagnose this disease, which is foolish when this disease seems to be the hardest to diagnose early or accurately…which means that there's many women out there concerned with itchy breasts who should be included in that number but still need to struggle it out to get a dx. Doesn't seem like a good number that represents true frequency in a population.
To me, the second would be more informative, although much harder to track since women seem to see multiple providers over time to ultimately get a diagnosis and be believed (how would you create this dataset, aside from longitudinal self-report from women).
And, the second one would be more psychologically calming (because I noticed people cite the 1-5% all of the time, but 1-5% of all possible breast-havers is a big number and 1-5% of "known cancers" is not helpful).
It would also be interesting to see "accuracy by provider" stats (yes, I am dreaming here; we don't have a feedback loop like that in the US). Like baseball players, it would be helpful to know that a provider has a high batting average at identifying concerning symptoms early vs. waiting.
Maybe I'm thinking about this population data wrong, but I haven't seen citations for where the 1-5% number comes from.
Maybe women would be diagnosed earlier if there wasn't so much indexing going on of "1-5%"
Comments
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Chrysanthemum79, I have not been on the site for a very long time. I was scanning the site to check on someone I know and I happened to see your post. I decided to break my "never sign in here again" rule to sign in and answer.
Let me address your questions and thoughts point by point.
What population does the 1-5% statistic represent?
- Does it represent the population of "all people in the US with Breasts"? (ie: the total alive population; this seems unlikely)
Approximately 12% of women in the U.S. will develop breast cancer during their lifetime. Fewer than 1% of all men will develop breast cancer during their lives. Therefore, of all adults in the U.S. with breasts, over their entire adult lifetimes (i.e. over a period of about 60 years), about 6.5% will be diagnosed with breast cancer of any type. IBC represents 1%-5% of that.
- Or, does 1-5% mean "anyone who presents at any doctor with any breast symptom or concern to include the things women get brushed off for frequently before ultimate diagnosis: itchy breast, bug bite, allergy, eczema, psoriasis.
Based on data I saw a few years back, of all patients who go to the doctor with any type breast concern or even just for imaging, approx. 0.5% end up with a diagnosis of some type of breast cancer. IBC would be 1%-5% of that.
- Or, is it representing of all dx cancer cases? In this case, it is of "known cancers" which relies too much on the ability to diagnose this disease, which is foolish when this disease seems to be the hardest to diagnose early or accurately…which means that there's many women out there concerned with itchy breasts who should be included in that number but still need to struggle it out to get a dx. Doesn't seem like a good number that represents true frequency in a population.
Yes, IBC represents 1%-5% of all breast cancers that have been diagnosed. But this percent has absolutely nothing to do with how easy or difficult it is to diagnose breast cancer or specifically, IBC. How long it takes to get to a diagnosis - whether 24 hours or 24 weeks - is irrelevant and has no bearing on the number of cases that are diagnosed; a delayed diagnosis is still a diagnosis and still counts in this aggregate number, which covers all cases of breast cancer and was developed based on years and years of data.
Maybe women would be diagnosed earlier if there wasn't so much indexing going on of "1-5%"What indexing? When a patient goes in to see a doctor, the doctor is looking at the patient and her symptoms. The doctor isn't thinking "Only 1-5% of cases of breast cancer are IBC so I will discount this patient's symptoms." What the doctor may be thinking is "There are 8 common symptoms associated with IBC. This patient has one symptom only, and this symptom is more frequently caused by a skin rash so let's check that out first." Or if the doctor is a PCP, they might simply be ignorant about IBC, in which case they certainly wouldn't be aware of the 1-5% statistic.
most women with IBC seem to be diagnosed once the IBC has caused the 'typical symptoms', many of these symptoms seem to imply that the BC had been in the breast causing "less obvious" symptoms for a while
IBC can be hard to diagnosis, not because there are "less obvious" symptoms but because individually, each of the "typical symptoms" is more likely to be caused by something other than IBC. If someone walks in with 3 or 4 typical IBC symptoms, the doctor will hopefully start investigating IBC right away. This is particularly true if the symptoms developed and worsened over a short period of time, because IBC tends to develop quickly. But if the patient has only 1 symptom (a rash or a small red patch, for example), the doctor will investigate the more likely causes first - which makes sense because ~99% of the time, the problem will be one of those more likely causes, not IBC. I spent years on this site, and I've seen hundreds of patients go through an extended diagnostic process which started with a single IBC symptom. Certainly a few did end up with a diagnosis of IBC, but the overwhelming majority - as in at least 95% of cases that I recall (probably more like 99%) - the patients did not end up with a diagnosis of breast cancer. This is not because the diagnosis was delayed because of skeptical or incompetent doctors, but because these patients really didn't have breast cancer.
Okay, signing off with no plans to ever return. Bye!
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And we still miss you, beesie!
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