Before You Consent: Breast Cancer

Guide 2: what to know, what to ask, and what to consider before you consent

She was sitting in a car park when she opened the letter. Callback. Abnormal finding. Further tests required. She hadn’t even turned the engine on yet.

By the time she got home she’d already Googled the survival statistics, read three terrifying forum threads, and started mentally dividing her life into before and after. Surgery was mentioned at the first appointment — within the same sentence as the diagnosis. A date was offered before she’d asked a single question. The whole thing moved like it had been scripted in advance, and she was the only person in the room who hadn’t read it.

She is not unusual. This is how the system works.

The compressed timeline — diagnose, schedule, operate — is not dictated by the biology of breast cancer. Most breast cancers have been growing for years before detection. The average preclinical phase is estimated at 21 years. A tumour must reach approximately one billion cells before it shows up on a mammogram, a process that takes 6 to 10 years. It did not appear last week. You have time. The system does not want you to know that.

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What the Numbers Actually Say

The 2014 Cochrane Review — the most rigorous independent analysis of mammography screening trials ever conducted — found this:

For every 2,000 women screened over 10 years, one may avoid dying from breast cancer. But 10 healthy women will be overdiagnosed and treated unnecessarily. And approximately 200 will experience false positive results leading to anxiety, biopsies, and further interventions.

No randomised trial has ever shown a reduction in all-cause mortality from mammography screening. Breast cancer mortality has declined since the 1990s, but the decline is observed equally in screened and unscreened populations, in countries with and without screening programmes. Improved treatments and awareness explain it. Screening does not.

Up to 60% of women who get annual mammograms for ten years will experience at least one false positive. For the 40–50% of women with dense breasts, mammogram accuracy drops to approximately 50% — dense tissue and cancer both appear white on the image. Most women are never told their breast density classification.

DCIS — ductal carcinoma in situ, classified as “Stage 0 cancer” — was virtually unknown before mammography. Diagnoses have risen from fewer than 5,000 to over 60,000 annually. Studies of women whose DCIS was missed at biopsy show that 75–89% never developed invasive cancer over 10–20 years. Only 3.3% of women diagnosed with DCIS die of breast cancer within 20 years, whether treated or not. The treatment does not change the outcome. It changes the experience — from a woman who never knew, to a woman who had surgery, radiation, or chemotherapy for something that would not have harmed her.

And the BRCA story is worse than most women realise. The 80–87% risk figures that drive decisions about prophylactic mastectomy come from families selected specifically because they had extreme cancer clustering. A 2007 analysis in the Journal of Medical Genetics found those figures are inflated by a factor of two to three. 35–55% of women with BRCA variants never develop breast cancer. A 2002 BMJ study found that women who’d already undergone prophylactic mastectomy overestimated their risk by more than 90%. The 18 women with the lowest computed risk believed their risk was 80%. Their actual computed risk was approximately 12%. They removed healthy breasts based on a belief that was wrong by a factor of seven.

These numbers are not hidden. They are published. They sit in the medical journals that inform the guidelines. They just never make it into the conversation in the exam room.

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From Knowing to Doing

That gap — between what the evidence says and what women are told — is what Breast Cancer: What They Didn’t Tell You documents across 195 pages. Mammography, BRCA genetics, root canal infections, iodine deficiency, hormonal IUDs, overdiagnosis, the financial architecture that holds it all together.

But knowing the evidence and knowing what to do with it are different things. Reading 195 pages at 2am after a diagnosis gives you information. It does not give you the three sentences you need to say to your oncologist on Thursday morning.

That is what Before You Consent is for.

It is the second in a series. The first — You’ve Just Been Prescribed a Statin — walked readers through the cholesterol conversation with their GP. This one does the same for breast cancer, but the stakes are higher and the decision tree is wider.

You start by identifying where you are. Four situations: called back after a screening mammogram. Diagnosed with DCIS. Diagnosed with invasive breast cancer. Told you should get BRCA testing or consider preventive surgery. The guide sends you to your branch.

Before the appointment, you absorb the evidence that reframes how you think about your diagnosis — what the label means, what the timeline actually is, what the proposed treatments do and don’t achieve in absolute terms.

During the conversation, you have the questions in front of you — and for each one, what your specialist will likely say and what the published data actually shows. When your oncologist says a treatment “reduces recurrence by 30%,” you know to ask for the absolute number. When a genetic counsellor quotes an 87% risk, you know to ask whether that figure was adjusted for ascertainment bias.

After the decision, two tracks. If you proceed with treatment: baseline tests worth discussing, symptoms to watch, monitoring intervals to raise with your prescriber. If you decline or delay: the upstream protocol documented in the literature — oral infections (Levy, Haley), iodine (Derry), hormonal disruption (Danish population studies), environmental toxins (Derflinger), metabolic support (Seyfried) — every dosage attributed to the researcher who published it.

At the back, two tearaway pages. A conversation card with three questions per branch that you can take into the appointment. A clinical checklist with baseline tests, monitoring schedule, and symptoms worth raising.

It is meant to be printed, carried into the room, and used.

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The Series

This is the second in the Before You Consent series. Each one is built for a specific moment — the moment you’re told something about your body and you need to know what to do before you agree to anything.

1. You’ve Just Been Prescribed a Statin — published

2. You’ve Just Been Told You Have Breast Cancer — this guide

3. You’ve Been Told Your Child Needs an ADHD Medication — in production

4. You’ve Just Been Prescribed an Antidepressant — in production

5. You’ve Just Been Told You Need a Prostate Biopsy — in production

The Insert Series reads the labels. The Questions Series arms you for the conversation. Before You Consent walks you through the decision itself — preparation, the appointment, and what comes after.

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The guide is attached below for paid subscribers.

If you know a woman who just got a callback, a diagnosis, or a recommendation she wasn’t ready for — send her this post. The evidence above the paywall is free. The action plan below it is what she’ll need on Thursday morning.