Doctors Sound the Alarm! The Truth About Genetic Tests That Recommend "Re-examination" for Women

"It's Okay Because It Was Negative"—Time to Reevaluate Genetic Testing for Cancer

"I had a genetic test before and it was negative." Some people may use this statement as a basis for long-term reassurance.

The Washington Post reported on the movement among doctors encouraging women who had early hereditary cancer tests to consider retesting.

To understand this topic, it's important not to interpret it as "old tests are unreliable." What needs to be confirmed is what the test examined, how much was understood, and whether there is a medical reason to investigate further now.

The Same "Negative" Doesn't Always Mean the Same Thing

In tests that examine hereditary cancer, a negative result basically means "no genetic changes were found that increase cancer risk within the scope of what was tested."

For example, if a specific pathogenic change is found in the family and it is confirmed that you do not have that change, it provides clear information that you have not inherited that family change. However, it does not guarantee immunity from cancer in general.

On the other hand, if there are many cancer patients in the family but no causative changes have been identified in any family members, a negative result may not fully rule out a genetic background.

It's necessary to read the test result in conjunction with the family situation, rather than looking at just one word from the results.

What Changes Is Not the Inherited Genetic Information but the "Scope of Investigation"

When hearing that retesting changed the results, one might feel, "Did the genes become positive with age?" However, the focus of this topic is the advancement of technology and knowledge in examining inherited genetic information.

The 2019 guidelines from the American Society of Breast Surgeons indicate that even those who were tested in the past might benefit from updated test content. Especially tests conducted before 2014 might not have included related genes like PALB2 or large structural changes in BRCA1 and BRCA2.

In other words, by examining genes that were previously excluded or looking for changes that were difficult to detect with previous methods, new information can sometimes be obtained.

However, there is no universal standard in Japan that mandates retesting for everyone tested before 2014. The actual test content varies by country, facility, and testing method.

Do Not Equate the Study's "17.3%" with Your Own Probability

As material for considering the usefulness of retesting, there is a study of 139 people who did not get a clear answer from past genetic evaluations and subsequently underwent retesting.

In this study, 24 people, or 17.3%, were found to have "pathogenic" or "likely pathogenic" genetic changes.

However, this is not a survey of randomly gathered general people. These are results from those who were connected to genetic medicine and underwent retesting. It cannot be applied to everyone as "about 1 in 6 people who were previously negative become positive."

In another study, 110 women who were negative for BRCA1 and BRCA2 underwent a 20-gene test, and 6, or 5.5%, were found to have pathogenic changes in genes other than BRCA.

The differences in numbers between studies reflect differences in subjects and test ranges. What should be considered is not just the size of the percentage but the reasons for taking the test and what was examined.

Even If the Number of Items Examined Increases, It Doesn't Always Lead to Clear Answers

Among the changes found in tests, there are those whose relationship with cancer cannot yet be determined. These are called "variants of uncertain significance," abbreviated as VUS.

This does not mean that a pathogenic change has been found.

The Japanese Hereditary Breast and Ovarian Cancer Comprehensive Care System Organization also explains that VUS interpretations may change in the future with research and data accumulation.

Here, we want to distinguish between "taking another blood test" and "re-evaluating previously found changes with new knowledge." Whether additional testing or re-evaluation of results is necessary will be determined by checking the report.

One should not hastily decide that a high cancer risk is present or rush into preventive surgery based solely on VUS.

On Social Media, Confusion Over Changing Results and Concern for Family

The social media reaction to this report itself was not sufficiently grasped within the confirmed range. However, on the BRCA-related community on the overseas forum Reddit, experiences about retesting have been shared for some time.

In a 2024 post, someone explained that although they were told BRCA1 and BRCA2 were negative in a previous test, they became BRCA2 positive in a test after developing another breast cancer, expressing confusion over the difference in results. The content was about wanting to verify the results to consider surgery, treatment options, and the impact on children.

Replies also included anecdotes of relatives who became positive in retests after previously being judged negative.

These are not case reports confirmed by medical records but posts by the individuals themselves. The cause of differing results cannot be determined from the posts alone.

Even so, the confusion of "I didn't think the results would change" and "How should I explain this to my family?" is conveyed. Explanations about tests should include not only the meaning of the results but also the possibility that information may be updated later.

In Japan, First Check the Previous Result Report

If you are concerned about retesting in Japan, the first useful action is to check the result report from the medical institution where you previously had the test.

When consulting, organizing the following information can facilitate the discussion.

• The time, facility, and name of the test you took
• The genes examined and the description in the result report
• The type of cancer you had and the age at diagnosis
• The types of cancer and ages at diagnosis of blood relatives
• Family illnesses or test results discovered after the previous test

The National Cancer Center explains that in genetic counseling, it is important to convey the medical history of yourself and your family to specialists. One method is to consult your primary care doctor and, if necessary, be referred to a specialized outpatient clinic for genetic medicine.

Consulting does not mean you must undergo testing. You should confirm beforehand what will change by knowing, the extent of the costs, and how to share the results with your family.

Even a Positive Result Does Not Determine Future Onset

Even if a pathogenic change is found, it does not mean "you will definitely get cancer" or "surgery is immediately necessary."

For example, for individuals with pathogenic changes in BRCA1 or BRCA2, screenings including breast MRI and risk-reducing surgeries may be considered, but choices involve age, medical history, pregnancy and childbirth desires, and personal values.

Moreover, the circumstances of early detection differ between breast cancer and ovarian cancer. The U.S. National Cancer Institute explains that for high-risk individuals related to BRCA, ultrasound and CA125 tests for ovarian cancer have not been established as effective screenings leading to long-term survival improvement. It cannot be simply stated that "frequent testing is sufficient."

The purpose of retesting is not to increase anxiety but to confirm whether information that can be used for future health management has increased.

Before Deciding "Whether to Test Again," Here Are Things to Ask

Not everyone needs to repeat the same genetic test every few years. It will be considered based on past test content, new medical history, and information learned about the family.

In consultations, you can ask questions like this:

"To what extent was the previous test conducted? Given my current and family situation, is there any significance in additional testing or reviewing the results?"

Reconnecting the memory of "it was negative" with a specific report and current medicine. This confirmation becomes the starting point for considering health management that suits you.

Sources and References

1. The Washington Post: Reporting on past hereditary cancer tests and retesting.
   https://www.washingtonpost.com/health/2026/10/12/women-once-cleared-by-genetic-tests-cancer-risks-now-consider-retesting/The Washington Post

2. U.S. National Cancer Institute (NCI): Explanation of the meaning of negative results and situations to consider additional or retesting.
   https://www.cancer.gov/about-cancer/causes-prevention/genetics/genetic-testing-fact-sheetNCI

3. American Society of Breast Surgeons 2019 Consensus Guidelines: Review of past tests and genes/structural changes that might have been excluded in old tests.
   https://pmc.ncbi.nlm.nih.gov/articles/PMC6733830/PMC

4. Study of 139 Retested Individuals: A study confirming pathogenic or likely pathogenic changes in 24 people, or 17.3%.
   https://pubmed.ncbi.nlm.nih.gov/34545504/pubmed.ncbi.nlm.nih.gov

5. Study of 110 BRCA Negative Women: A study where 6 individuals were found to have pathogenic changes in non-BRCA genes after retesting 20 genes.
   https://pubmed.ncbi.nlm.nih.gov/31784482/PubMed

6. Japanese Hereditary Breast and Ovarian Cancer Comprehensive Care System Organization: Explanation of VUS and the possibility of its interpretation being updated.
   https://johboc.jp/guidebook_g2022/q19/johboc.jp

7. Reddit "Previous negative test now positive.": Posts and replies about changed results in retesting. Referenced as past self-reported experiences, not reactions to this report.
   https://www.reddit.com/r/BRCA/comments/1cqsib4/previous_negative_test_now_positive/

8. National Cancer Center "Hereditary Tumors": Contents of genetic counseling consultations, organizing medical history, and consultation destinations in Japan.
   https://ganjoho.jp/public/cancer/hereditary_tumors/index.htmlganjoho.jp

9. NCI "BRCA Gene Changes": Interpretation of positive results, risk management options, and limitations of ovarian cancer screening.
   https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet