There’s one tip I learned this year that could save your life, or minimize your suffering. Especially if you are an Ashkenazi Jewish woman.

Six months ago, my coworker Leila and I were diagnosed with breast cancer on the same day. We went through the various stages of our treatment virtually in tandem. But my cancer was found at Stage 0 and hers was found at Stage 1. While mine was found by mammogram when it was tiny micro-calcifications, Leila found hers when it was already a palpable lump.

At each stage of our treatment, Leila’s suffering served as a reminder of how lucky I was that my cancer was diagnosed extremely early. My lumpectomy knocked me out for two days, after which I had to force myself to rest for the balance of the recommended recuperation week. Leila’s surgery, which involved a lymph node, put her out of commission for weeks, resulted in lymphedema, and left her with a frozen shoulder that required physiotherapy. My month of radiation therapy caused extreme itchiness, mild tiredness, and moderate pain and discomfort; hers yielded intense fatigue, severe burns, and edema that may require further surgery to resolve.

Happily, neither of us had to undergo chemotherapy or have a mastectomy, which could have been necessary at later stages or if the nature of our particular cancers had been different.

It’s important to remember that while breast cancer was once thought to strike one in nine women, according to current figures, approximately one in eight women will develop invasive breast cancer during the course of their lifetime. Among Ashkenazi women, the rate is said to be as high as one in seven.

Once you are admitted to the cancer club, you see just how many women that is. Suddenly, you discover that the woman sitting next to you in synagogue, your co-worker’s sister, and your neighbor’s mother have all been through the same thing. You find yourself swapping intimate details with casual friends and acquaintances—brave, open women, who share the trauma of confronting their mortality, the affront to their body and body image, the fear of recurrence, and first-hand knowledge of a vast range of pathologies and side effects.

So in the year to come, don’t put off your mammogram! Yes, it’s painful, unpleasant, and likely to make you wonder whether better alternatives would have been found if a similar test was necessary for diagnosing testicular cancer. But at the moment, mammography is still the best way of detecting breast cancer at its earliest stages, and as I have learned, the difference between treatment at early and later stages can be enormous.

Remember too that sometimes your health is literally in your own hands. My friends Cathy and Rachel detected their cancers during monthly breast self-examinations. (The names in this article have all been changed, but ladies, you know who you are.) Nadine’s first cancer was caught by mammogram, but her three (!) subsequent occurrences were found by self-exams. So set a time each month to check. Link it to your menstrual cycle, your visit to the mikveh, your paycheck, the first day of the month on the Gregorian or Jewish calendar.

As you approach the New Year, don’t suffice with pleading “Our Father, our King, Inscribe us in the book of life” and “Send a complete recovery to the sick of Your people.” Resolve not to put off your mammogram; commit to remembering your monthly self-exam. You owe it to yourself, your children, and your loved ones.

Today, I know that I have no choice in the matter. And if you too are one of those “one in eight” or “one in seven,” you may not know it yet, but neither do you.