# Do all pre-cancerous growths become cancerous? **URL:** \ **Category:** Factual Questions\ **Created:** [January 26, 2018, 3:10pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524 "2018-01-26T15:10:51Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [January 26, 2018, 3:10pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/1 "2018-01-26T15:10:51Z")
How do doctors know that a growth is pre-cancerous? If it will definitely become cancerous, then why don’t they call it a cancerous growth at the time of discovery? I have friends who have had many many treatments to remove pre-cancerous growths, and I have come to wonder if this is not so much a major advance in medicine but rather a source of income based as much or more on fear as it is on science. How do doctors predict the future with these growths? Clearly this comes from statistics and data. What do they show? ---
**Author:** ![buddha\_david](https://avatars.discourse-cdn.com/v4/letter/b/ee7513/32.png) [@buddha\_david](https://boards.straightdope.com/u/buddha_david)\ **Post date:** [January 26, 2018, 3:44pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/2 "2018-01-26T15:44:11Z")
> [@CC](#): > > I have come to wonder if this is not so much a major advance in medicine but rather a source of income based as much or more on fear as it is on science. If it was really about money, doctors would wait until the growths became cancerous, since cancer treatments are far more expensive. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 26, 2018, 3:52pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/3 "2018-01-26T15:52:36Z")
In many cancers, a series of mutations must take place in order for a cell line to become malignant. Pre-cancerous cells may have some of these mutations, and some characteristics of cancer, but not all of them. It may be a matter of chance when the next mutation develops; not all such growths become cancerous. So it’s best to remove or treat them rather than wait till the last step in development takes place. An analogy would be being dealt cards in a hand of poker. Let’s say having five spades means you get full-blown cancer. Having three or four spades is pre-cancerous. You want to get rid of them before you’re hit with that last spade. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 26, 2018, 3:57pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/4 "2018-01-26T15:57:07Z")
From the Wiki entry on cancer: > [@](#): > > All tumor cells show the six hallmarks of cancer. These characteristics are required to produce a malignant tumor. They include:[26] > > Cell growth and division absent the proper signals > > Continuous growth and division even given contrary signals > > Avoidance of programmed cell death > > Limitless number of cell divisions > > Promoting blood vessel construction > > Invasion of tissue and formation of metastases[27] > > The progression from normal cells to cells that can form a detectable mass to outright cancer involves multiple steps known as malignant progression Pre-cancerous cells will show some but not all of these characteristics. ---
**Author:** ![CC](https://avatars.discourse-cdn.com/v4/letter/c/f1d935/32.png) [@CC](https://boards.straightdope.com/u/CC)\ **Post date:** [January 26, 2018, 4:07pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/5 "2018-01-26T16:07:05Z")
I read that Wiki entrance. I still cannot understand how a dermatologist can look at a spot on the skin and declare them pre-cancerous. It would seem that none of the characteristics listed could be determined by a naked eye exam. I don’t want 5 spades, but how can the doctor determine that I’m holding 3 or 4 without doing a more in-depth biopsy? I guess I’m basing my skepticism on reports that doctors have told people “This spot looks pre-cancerous and we should remove it.” p.s. A dermatologist who removes these things all day makes a lot of money - more than if s/he removed one definitely cancerous growth. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [January 26, 2018, 5:16pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/6 "2018-01-26T17:16:17Z")
The way to know with the greatest possible certainty if a skin lesion is cancerous is to take it off (or at least remove an adequately sized piece of it) and do studies on it. I don’t tend to pronounce lesions that I see as “cancerous” or “pre-cancerous”. I look at it, and perhaps others on the body, and the patient’s past history, and if there are enough red flags by this time, say “that raises enough concerns for possible malignancy that I think (and community standards agree) that we ought to biopsy it”. I get paid a flat salary, so I only remove things that I think need to be removed. And I’m a Family Medicine doc, so I am also busy doing other things than looking at skin. That said, a dermatologist with lots of experience probably has a moderately accurate guess from just looking at a lesion as to whether the biopsy will show cancer, or or suspicious changes, or whatever. Also: not all pre-cancerous lesions turn into cancer; some persist without change, some resolve, or go back to looking normal. The body manages to police a lot of that stuff on its own. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [January 26, 2018, 6:03pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/7 "2018-01-26T18:03:51Z")
> [@CC](#): > > I guess I’m basing my skepticism on reports that doctors have told people “This spot looks pre-cancerous and we should remove it.” p.s. A dermatologist who removes these things all day makes a lot of money - more than if s/he removed one definitely cancerous growth. You’re basing your opinion on “reports” rather than first-hand experience? Perhaps you don’t have all the details of what precisely the doctor said and the factors that went into his or her decision. And how do you know how much money is charged for removing a pre-cancerous vs a cancerous growth?:dubious::dubious::dubious: A dermatologist who looks at these things all day long probably has a pretty good idea of which growths could be problematic. You also have to look at the cost vs the risk of doing nothing. Personally, if I had a growth that had a one-in-a-thousand chance of turning into cancer I’d probably prefer to have it removed. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [January 26, 2018, 6:23pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/8 "2018-01-26T18:23:28Z")
The day is coming when reliable molecular testing will tell us which “pre-cancerous” lesions are likely to develop into invasive carcinoma (and which low-grade invasive lesions will have metastatic potential)) and which lesions will stay at their current level or even regress. This will be an enormous benefit to women with ductal carcinoma in situ and atypical ductal hyperplasia, men with low grade prostatic adenocarcinomas, those with atypical melanocytic skin lesions etc. We already know that most human papillomavirus infections will eventually be cleared by the body. The problem is, we can’t yet tell which will progress to high grade dysplasias and carcinomas, so continued surveillance and in some cases surgery are needed. To those who think MDs are rubbing their hands together with glee over collecting fees for diagnosing and treating “pre-cancerous” lesions, remember that docs are not immune from getting these lesions and undergoing biopsies and resections themselves (not to mention relatives and friends). We will all be happy when only the necessary lesions get excised. I’d be overjoyed if they didn’t feel it necessary to biopsy every pissant thing that shows up on mammography and/or breast MRI and send me tons of borderline stuff that likely is meaningless in the long run, but we can’t be sure right now). One bit of good news - there’s progress on [a blood test](https://www.livescience.com/61494-cancer-blood-test.html) to diagnose a number of different cancers, potentially minimizing the need for colonoscopies and other invasive procedures. It can’t come soon enough. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [January 26, 2018, 6:31pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/9 "2018-01-26T18:31:08Z")
> **[Addressing overdiagnosis and overtreatment in cancer: a prescription for change](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4322920/)** > > A vast range of disorders—from indolent to fast-growing lesions—are labelled as cancer. Therefore, we believe that several changes should be made to the approach to cancer screening and care, such as use of new terminology for indolent ... > [@](#): > > About 2·2 million predominantly older (\>65 years) Americans are diagnosed with non-melanoma skin cancers every year, including basal-cell and squamous-cell cancers.51 The number diagnosed and given aggressive treatment has risen by more than 50% in the past decade.52,53 Except in some small, immunosuppressed populations, basal-cell and squamous-cell carcinoma are rarely fatal. If left untreated (for years), they can cause local problems, some serious. \*\*Despite less invasive treatment options being available, the proportion of aggressive surgical procedures done in patients with limited life expectancy is almost the same as in healthy individuals.\*\*51 Non-melanotic skin cancer is a candidate for change in terminology to promote safe alternatives to large excision or Mohs’ surgery, such as observation. > > **Melanoma diagnoses have increased worldwide, but the rise is predominantly due to stage I melanoma diagnoses, without a drop in mortality.** This increase has been ascribed to a rising proportion of patients undergoing biopsy, and to stage-drift (ie, a shift over time in how types of lesions are defined; for example, tumours once considered to be in situ might now be defined as stage I).54,55 Melanoma, however, is an important disorder and can be lethal. Incidence and mortality have increased, despite a huge increase in the excision of benign skin lesions.9,56 The challenge for the community is to establish what will reduce the incidence of consequential cancers and their attendant mortality. Resources and efforts should be focused strategically. ---
**Author:** ![Blue\_Blistering\_Barnacle](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blue_blistering_barnacle/32/3386_2.png) [@Blue\_Blistering\_Barnacle](https://boards.straightdope.com/u/Blue_Blistering_Barnacle)\ **Post date:** [January 27, 2018, 1:40am UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/10 "2018-01-27T01:40:30Z")
> [@Qadgop\_the\_Mercotan](#): > > …snipped… > > Also: not all pre-cancerous lesions turn into cancer; some persist without change, some resolve, or go back to looking normal. The body manages to police a lot of that stuff on its own. An obvious, but to many unhelpful, example of a precancerous lesion not becoming cancer, is if the patient dies of something else first. You may have a skin lesion, schedule a biopsy, and get killed in a car crash on the way to your procedure. This is more relevant than most would think. If precancerous lesions (and cancers) are diagnosed in people with short life expectancies, they may not be benefited by diagnosis and treatment. This is an issue with screening mammograms. Also, especially in breast, prostate, and thyroid, we have become aware of the existence of histologic cancers (which may be found on biopsies) which do not go on to ultimately behave like cancers. This is inferred from screening programs which led to significant increases in diagnosis rate\* without increasing mortality rate\*\*. \*diagnosis rate may go up at the beginning of a screening program, as smaller subclinical tumors may be found, which otherwise may have manifested in several years. However, this should stabilize and revert to prior levels if the cancer rate is stable. \*\*Dr. Pangloss believes that the mortality rate is not increasing because the small tumors are all being successfully treated, so mortality rate stays stable despite rising cancer rate. Yay, medicine! But this is felt to be overoptimistic by epidemiologists. For example, not everyone gets screened equally well, some groups fall through the cracks. These groups should see significantly increased rates of death from cancer if the incidence of real cancers was rising. The last explanation is overdiagnosis. This would take a systematic review of biopsy samples to detect. It is currently believed that some cells that “look like cancer” would not go on to “behave like cancer”. This may change with improved techniques. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [January 27, 2018, 4:11am UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/11 "2018-01-27T04:11:28Z")
In the last decade or so we’ve seen an overall decline in _both_ cancer diagnoses and cancer deaths in the United States. Beyond screening programs like those for colon cancer resulting in polyps being removed before invasive tumors can develop, there are other explanations for a lower rate of new cancer diagnoses, including diminished use of the PSA test to look for prostate cancer (many of these cancers would not have gone on to result in symptomatic malignancies), and the continued drop in smoking. Re thyroid malignancies - one type of thyroid cancer has actually become obsolete. The encapsulated follicular variant of papillary thyroid carcinoma has been reclassified to reflect knowledge that it behaves in a benign fashion, despite morphologically resembling a type of malignant papillary carcinoma. From a Medscape article: _“An international panel of pathologists and clinicians has reclassified a type of thyroid cancer to reflect that it is noninvasive and has a low risk for recurrence. The panel renamed encapsulated follicular variant of papillary thyroid carcinoma (EFVPTC) as noninvasive follicular thyroid neoplasm with papillary-like nuclear features (NIFTP). “To my knowledge, this is the first time in the modern era a type of cancer is being reclassified as a noncancer. I hope that it will set an example for other expert groups to address nomenclature of various cancer types that have indolent behavior to prevent inappropriate and costly treatment,” senior investigator Yuri Nikiforov, MD, PhD, director of the Division of Molecular and Genomic Pathology, University of Pittsburgh School of Medicine, Pennsylvania, said in a statement.”_ A problem with this new classification is that diagnoses of thyroid cancer are often based on cytologic evaluation (fine needle aspiration of a thyroid lesion), and it is not yet possible to make a definitive diagnosis of NIFTP on a cytology specimen (a surgical resection is required). So some patients may still get unnecessary removal of part or all of their thyroid gland. ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [January 27, 2018, 4:29am UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/12 "2018-01-27T04:29:48Z")
> [@Jackmannii](#): > > We already know that most human papillomavirus infections will eventually be cleared by the body. The problem is, we can’t yet tell which will progress to high grade dysplasias and carcinomas, so continued surveillance and in some cases surgery are needed. Indeed. Both my ex and I - apparently - are HPV-16 positive. Ten or so years ago - you can look up the thread if you try - she was diagnosed with pre-cancerous cervical cells and a surgery was done to remove them. Last year, I was diagnosed with HPV-related throat cancer. It required months of radiation and weeks of chemo. I’m better now - clear scan two months ago - but that’s an illustration of pre-cancerous and cancerous. ---
**Author:** ![mr\_horsepower](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@mr\_horsepower](https://boards.straightdope.com/u/mr_horsepower)\ **Post date:** [January 27, 2018, 6:29am UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/13 "2018-01-27T06:29:08Z")
> [@Jonathan\_Chance](#): > > Last year, I was diagnosed with HPV-related throat cancer. It required months of radiation and weeks of chemo. I’m better now - clear scan two months ago - but that’s an illustration of pre-cancerous and cancerous. did you have any symptoms or were you being screened as a result of her diagnosis? if you did have symptoms, what were they? and just because that was cleared up you still have HPV, right? if so, what are the odds of this occurring again? ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [January 27, 2018, 3:14pm UTC](https://boards.straightdope.com/t/do-all-pre-cancerous-growths-become-cancerous/807524/14 "2018-01-27T15:14:24Z")
> [@mr\_horsepower](#): > > did you have any symptoms or were you being screened as a result of her diagnosis? > > if you did have symptoms, what were they? > > and just because that was cleared up you still have HPV, right? > > if so, what are the odds of this occurring again? I had a swelling on my neck of which I was unaware until my GP noticed it. According to the literature some immune systems can defeat HPV and some simply don’t so I don’t know, truly. The odds of recurrence seem small from what I’m told, but I’m getting scans every six months for several years to keep an eye on things. Best, safe than sorry.