September is cancer awareness month for advocates promoting concern about leukemia and lymphoma, childhood, gynecological, ovarian, prostate and thyroid cancers. Those honorable advocates are driving home the two central truths we’ve always been taught about cancer—that we should always find it as early as possible, when it’s most treatable, because as the second belief holds, cancer always kills.

Neither of those now-outdated beliefs is still true. What is true is that those beliefs are doing serious harm all by themselves. Those beliefs are, in fact, causing serious and avoidable health damage – including death itself – to tens of thousands of people. We desperately need a more modern emotional relationship with the disease we the most.

Not all cancers are the same. While they all involve cells growing without normal controls, not all of them kill. We have learned in the past few decades that some cancers grow so slowly (some don’t grow at all) that they never cause symptoms in the person’s lifetime. These include some common types of breast, prostate, thyroid, and lung cancer. But our belief that we should always find cancer as early as possible has led to the development of perceptive new screening tools that can now spot many tiny early cancers that will never cause any harm. But because they have the word "cancer" in the diagnosis, we react by choosing all sorts of tests and treatments that do more damage than the disease ever would.

Overscreening and overtreatment for diseases that scare us but don’t actually threaten us is just one aspect of what surgeon Dr. Barney Crile Jr. called cancerphobia in his Life Magazine article, “A Plea Against The Blind Fear of Cancer." “It is possible today,” he wrote, “that, in terms of the total number of people affected, fear of cancer is causing more suffering than cancer itself.” Crile Jr. wrote that in 1955. It may be even more true now.

Consider a few figures from a book I’m working on (calculations based on data from the National Cancer Institute and data from numerous medical journals):

Over the roughly 40-year lifetime of popular mammography, while screening has undoubtedly saved thousands of lives, it has also caught so many low-risk cancers that roughly 800 women have died from surgical complications after lumpectomies or mastectomies (or double mastectomies, which provide no clinical risk reduction compared to single breast surgery) to remove low-grade ductal carcinoma in situ (DCIS), which in most cases never causes any harm. Over the lifespan of mammography, 210,000 women have suffered long-term Post Mastectomy Pain Syndrome from these operations. 750,000 have suffered often harsh side effects from the adjuvant radiation or chemotherapy that often follows such surgeries.

Over the 25 years of popular PSA screening for prostate cancer, that test has ultimately led 565,000 men to have prostatectomies to remove the slow-growing and essentially non-threatening form of that disease, resulting in approximately 1,900 surgery-related deaths, 376,000 men with long-term , 113,000 men with long-term urinary incontinence, and nearly 85,000 men who have trouble controlling their bowels.

The same thing is happening with thyroid cancer. More is being discovered, but nearly all of it is non-threatening. Thousands of people are enduring the side effects of thyroidectomies, surgery to remove the gland that helps control basic metabolism, including the fatigue and weight gain of hypothyroidism, partially damaged or paralyzed vocal cords, and in rare cases death itself, to remove a disease with a scary name that almost certainly never would have harmed them.

It’s even occurring with low dose helical computerized tomography (LDCT) to screen for lung cancer, first recommended in the U.S. (but only for heavy current or former smokers) just six years ago. (The U.K. doesn’t recommend it at all.) A large random clinical trial estimates that LDCT screening may have saved as many as 6,000 lives in those six years, a phenomenal success. But that trial also found that such screening sometimes spots slow or non-growing cancers in elderly patients (the average lung cancer patient is 65), many of who have other health issues, and surgery in these vulnerable people, for cancers unlikely to harm or kill them in their lifetime, has killed an estimated 840 people, and caused serious health problems like strokes, heart attacks, and infections requiring extensive hospitalization, for roughly 10,000.

And these figures don’t include the tens of millions of people who have endured the frightening experience of a false positive, an initial finding that the screen found something suspicious that after further screening or invasive biopsy turns out not to be cancer. This is a particular problem with mammography and lung cancer screening. Psychosocial research has established that these scary false alarms cause long-term and worry in as many as one in five people. Cruelly, as a result of these false positives, tens of thousands of people every year who go for screening because they are afraid of cancer, and who are told at first that they might have the disease only to find out that they don't, end up permanently more worried they’ll develop it.

Those are only the harms that cancerphobia causes to individuals. Our excessive fear of this often dreadful disease also imposes massive costs on society. Overtreatment causes hundreds of billions of dollars in unnecessary health care spending. Fear that, as Joe Jackson sang “Everything causes cancer,” leads us to spend hundreds of billions on all sorts of products and services that promise protection from environmental carcinogens (like paying premium prices for pesticide-free organic food despite the absence reputable research that this reduces cancer incidence), even though experts estimate that roughly two thirds of all cancers are simply diseases of aging, triggered by naturally occurring mutations, not by exposure to external substances (75% of all cancers occur in people over 55). Cancerphobia makes us afraid of all sorts of things “out there," readily suspicious of new products or technologies and driving resistance to cell phone towers, high-tension power lines, and of course to nuclear energy (radiation), which could help us fight the massively greater risk of . It drives massive jury verdicts against various companies even when the scientific evidence of harm from one of those company’s products is speculative at best. The list goes on.

There is no doubt that cancer is often a terrible affliction. Most of us have suffered its cruelty first hand, or in family or friends. There is also no doubt that fear of cancer is deep and real, and that the choice any individual makes to be free of the fear of cancer, in the context of his or her own life, is right for that individual, and not for me or any outsider to judge as right or wrong, rational or emotional.

But as a society, we desperately need to modernize our emotional relationship with the Emperor of All Maladies. Our blanket fear of anything associated with the “C” word, and our blind belief that more screening is always good, beliefs rooted in what we used to know about cancer but is now outdated, are doing us great harm, in many cases more than the disease itself. As we struggle to find the cure for all cancers, we should also work to recognize and cure our cancerphobia. They are both dangerous.