Prostate cancer can be inherited from either parent. The key gene mutations linked to the disease, including those in BRCA2, BRCA1, HOXB13, and several DNA-repair genes, sit on non-sex chromosomes and follow inheritance patterns that make a mother just as likely to pass them along as a father. That said, the question is more interesting than the simple answer suggests, because there is real evidence pointing to the X chromosome as an additional source of risk, which would implicate the maternal line specifically.
More Than Half of Risk Is Inherited
Prostate cancer is one of the most heritable cancers in humans. According to the National Cancer Institute, more than half of a man’s prostate cancer risk comes from what he inherited from his parents. For most men, the inherited portion is not a single dramatic mutation but the combined effect of hundreds of common genetic variants, each nudging risk up by a small amount. Only a minority carry one of the high-risk mutations that substantially change the odds on their own.
The mutations that matter most for inherited prostate cancer risk, including changes in BRCA1, BRCA2, HOXB13, ATM, CHEK2, and the genes behind Lynch syndrome, all sit on autosomes, the numbered chromosomes that everyone inherits equally from both parents. They follow an autosomal dominant pattern, meaning a single altered copy is enough to raise cancer risk. If one parent carries such a mutation, each child has a roughly 50 percent chance of inheriting it, regardless of whether that parent is the mother or the father.1Prostate Matters. Genetics and prostate cancer
BRCA Mutations and the Breast Cancer Link
When people hear “BRCA,” they usually think of breast and ovarian cancer in women. But BRCA mutations raise prostate cancer risk too. BRCA2 in particular is the most commonly altered gene in men diagnosed with prostate cancer before age 65, and men who carry a BRCA2 mutation face a higher chance of developing an aggressive form of the disease with shorter survival times.2PubMed Central. BRCA2 gene mutation and prostate cancer risk. Comprehensive review and update
This is where the maternal side of the family becomes especially relevant. Because BRCA mutations are so strongly associated with breast and ovarian cancer, they are far more likely to have been identified and documented in a family through a woman’s diagnosis. A man whose mother, sister, or maternal aunt had breast cancer may be carrying the same BRCA mutation that also raises his own prostate cancer risk. The mutation did not skip a generation or travel through some sex-specific pathway; it simply sat on a non-sex chromosome and was passed along the way any autosomal gene would be. The difference is purely one of visibility: the family noticed the breast cancer diagnosis in a female relative but may not have connected it to prostate cancer risk in the men.
Several large studies have quantified this connection. In one prospective cohort, men whose family included a breast cancer diagnosis had about a 21 percent higher risk of being diagnosed with prostate cancer overall, and a borderline 34 percent higher risk of lethal prostate cancer, compared to men with no family history of breast cancer.3PubMed Central. Family history of breast or prostate cancer and prostate cancer risk Another study found that having a mother or sister with breast cancer was associated with roughly a 22 percent increase in prostate cancer risk.4PubMed Central. Family history of prostate and breast cancer and the risk of prostate cancer in the PSA era A third analysis, using data from a large cancer-screening trial, confirmed the association: men with a first-degree relative who had breast cancer were more likely to be diagnosed with prostate cancer themselves.5PubMed. Evaluating Family History Links between Breast Cancer and Prostate Cancer Among PLCO Trial Participants
The practical upshot is that when you are gathering your family cancer history, you should not limit your attention to male relatives who had prostate cancer. Breast cancer in your mother, your sisters, or your maternal grandmother is a signal worth paying attention to.
The X-Chromosome Hypothesis
Beyond the autosomal genes, there is a genuinely intriguing line of research suggesting that part of prostate cancer risk may come specifically from the mother through the X chromosome. Men have one X chromosome, inherited exclusively from their mother, and one Y chromosome from their father. A study published in Nature Medicine found that men who had an affected brother were at greater risk of prostate cancer than men who only had an affected father. That pattern is consistent with an X-linked or recessive model of inheritance, because brothers share their mother’s X chromosome roughly half the time, while a father’s prostate cancer would be passed on through autosomal genes shared equally with sons and daughters.6PubMed. Evidence of an X-linked or recessive genetic component to prostate cancer risk
If confirmed, this would mean that at least one component of prostate cancer susceptibility travels through the maternal line in a way that is genuinely sex-specific. A woman could carry a prostate cancer risk variant on one of her two X chromosomes without ever being affected herself, since she has a second X to compensate. Her sons would have no such backup. The hypothesis has been around since the mid-1990s and has not been fully resolved. Researchers have identified candidate regions on the X chromosome, but no single X-linked gene has been pinned down as a definitive prostate cancer susceptibility locus. The idea remains plausible rather than proven, and it sits alongside the autosomal story as an additional layer rather than a replacement for it.
The Y Chromosome and the Paternal Side
The father’s unique genetic contribution, the Y chromosome, also appears to play a role, though in a different way. The Y chromosome is unusually vulnerable to mutations because it is replicated exclusively in sperm cells, which develop in the oxidative environment of the testis. Accumulated damage and epigenetic changes on the Y chromosome have been linked to both the development and the progression of prostate cancer.7PubMed Central. Prostate cancer susceptibility and growth linked to Y chromosome genes
Loss of parts of the Y chromosome, sometimes called “loss of Y” or LOY, is increasingly recognized as a feature of aging in men and has been associated with several cancers. For prostate cancer specifically, the Y chromosome carries genes involved in regulating cell growth and immune surveillance in the prostate. When those genes are damaged or silenced, the brake on abnormal cell growth may weaken. Unlike the autosomal mutations discussed above, Y-linked changes are passed from father to son and cannot come from the mother at all. This means that while most inherited prostate cancer risk is shared equally between both parents, there is a small and still-emerging body of evidence suggesting that the paternal Y chromosome contributes its own specific vulnerabilities.
HOXB13 and Other High-Risk Genes
Beyond BRCA, a handful of other genes carry mutations that substantially increase prostate cancer risk. HOXB13 is among the most studied. A specific mutation in this gene, called G84E, was found at about 20 times the expected rate among men of European descent who had prostate cancer. The mutation was especially overrepresented in men with early-onset, familial disease: about 3.1 percent of men with both a young diagnosis and a family history carried the G84E mutation, compared to about 0.6 percent of men with late-onset prostate cancer and no family history.8PubMed Central. Germline mutations in HOXB13 and prostate-cancer risk
Like BRCA, HOXB13 sits on an autosome (chromosome 17), so it follows the same inheritance rules: either parent can pass it on. Mutations in ATM and CHEK2, two other DNA-repair genes, similarly sit on autosomes and are inherited without regard to which parent carries them. Each of these genes plays a different role in maintaining the integrity of DNA, and mutations in any of them impair the cell’s ability to fix errors, which over time increases the probability of cancer developing.
Lynch Syndrome and Prostate Cancer
Lynch syndrome is best known for dramatically raising the risk of colon and endometrial cancer, but it also raises the risk of prostate cancer, and this connection often gets missed. Lynch syndrome is caused by inherited mutations in DNA mismatch repair genes, including MLH1, MSH2, MSH6, and PMS2. These genes are responsible for catching and fixing small errors that accumulate every time a cell divides.
A study that compared the observed rate of prostate cancer among Lynch syndrome carriers to what would be expected in the general population found that the rate was about five times higher. Out of the carriers studied, the observed number of prostate cancer cases was roughly five times the expected count, yielding a standardized rate ratio of 4.87.9PubMed Central. Prostate cancer incidence in males with Lynch syndrome Like the other gene mutations discussed above, Lynch syndrome is autosomal dominant, meaning it can come from either parent. Families that already know they carry Lynch syndrome because of colon cancer diagnoses should be aware that male family members have elevated prostate cancer risk as well.
The Polygenic Piece
For every man who carries a single dramatic mutation, many more carry a collection of common genetic variants that individually do almost nothing but together add up to meaningful risk. Researchers compress these into a polygenic risk score, or PRS, which sums up the small contributions of hundreds of known risk-associated genetic markers.
A recent study found that men whose PRS was at or above the median had roughly three times the risk of developing prostate cancer compared to men below the median. The association with dying from prostate cancer was similar in magnitude. Among men diagnosed between ages 65 and 74, the risk associated with a high PRS was even more pronounced.10Nature. Polygenic risk score and 20-year prostate cancer-specific mortality and survival
None of these individual common variants comes specifically from the mother or the father. Each one is inherited the same way any single-letter genetic variant would be: a random coin flip at each position. The polygenic component of risk is spread across the entire genome, and the parental side it comes from is essentially a matter of chance at each position. In practice, this means that the bulk of heritable prostate cancer risk is not traceable to one side of the family. It is a mosaic assembled from both parents.
Why the Maternal Family History Often Gets Overlooked
A persistent misconception is that prostate cancer history only matters on the father’s side of the family, since only men have prostates. This is wrong in two ways. First, as covered above, the gene mutations that raise prostate cancer risk sit on autosomes and pass equally from mothers and fathers. A mother who carries a BRCA2 or HOXB13 mutation passes it to her sons just as readily as a father would. She simply never develops prostate cancer herself, so the mutation’s presence in the family may manifest as breast or ovarian cancer rather than prostate cancer.
Second, the family history that should raise your antenna is broader than prostate cancer alone. A large multi-institutional study found that having a first-degree relative with breast cancer increased the adjusted odds of being diagnosed with high-grade prostate cancer by about 30 percent. That is in the same ballpark as the effect of having a second-degree relative with prostate cancer itself.11European Urology. Defining the Impact of Family History on Detection of High-grade Prostate Cancer in a Large Multi-institutional Cohort Men who report “no family history of prostate cancer” but whose mothers had breast cancer at a young age are, in a sense, reporting their family history incompletely.
When Genetic Testing Makes Sense
Not every man needs genetic testing for prostate cancer susceptibility, but guidelines have been expanding in recent years. A scoping review of clinical guidelines found broad agreement that germline testing is recommended for men who already have high-risk or metastatic prostate cancer, regardless of their family history. Testing is also recommended for men whose families include early-onset breast cancer (diagnosed at age 50 or younger), ovarian cancer at any age, pancreatic cancer, prostate cancer diagnosed before 60, death from prostate cancer, Lynch syndrome-related cancers diagnosed before 50, or Ashkenazi Jewish ancestry.12Nature. Guidelines for genetic testing in prostate cancer: a scoping review
Notice how many of those criteria point to cancers that are more commonly diagnosed in women. Ovarian cancer, early-onset breast cancer, and endometrial cancer are all flags that a BRCA or Lynch syndrome mutation may be circulating in the family. A man whose maternal grandmother died of ovarian cancer and whose mother had breast cancer at 45 would meet multiple criteria, even if no man in his family has ever been diagnosed with prostate cancer. The guidelines effectively encode the biological reality that these mutations travel through both parents.
Epigenetics and Imprinted Genes
Beyond the DNA sequence itself, there is growing interest in whether the parent-of-origin changes how certain genes behave in the prostate. Humans carry a set of “imprinted” genes whose activity depends on which parent they came from: the copy inherited from one parent is silenced, while the copy from the other parent is active. When the molecular marks that control this silencing go wrong, a gene that should be switched off may turn on, or vice versa.
In prostate cancer research, the imprinted gene that has gotten the most attention is IGF2 (insulin-like growth factor 2), which promotes cell growth. Under normal conditions, only the paternal copy of IGF2 is active. If epigenetic disruption causes both copies to switch on, cells in the prostate receive a stronger growth signal than they should. Research has documented expression changes for IGF2 in cancerous prostate tissue, though the broader landscape of imprinted gene dysregulation in prostate cancer is still poorly mapped.13PubMed Central. Specific changes in the expression of imprinted genes in prostate cancer–implications for cancer progression and epigenetic regulation This is a frontier area rather than an established clinical factor, but it hints that which parent a gene comes from could matter in ways that go beyond what the DNA sequence alone would predict.
How Inherited Mutations Affect Treatment
Knowing whether your prostate cancer has a hereditary component is not just a matter of understanding risk. It can change how the disease is treated. Men with mutations in BRCA2 and other DNA-repair genes have shown improved responses to a class of drugs called PARP inhibitors, which exploit the cancer cell’s broken repair machinery to kill it.14PubMed. The Role of BRCA Testing in Hereditary Pancreatic and Prostate Cancer Families Several PARP inhibitors are now approved for use in metastatic prostate cancer that carries qualifying mutations.
This is one of the clearest examples of precision medicine in oncology. A man diagnosed with advanced prostate cancer who undergoes genetic testing and discovers a BRCA2 mutation gains access to a treatment pathway that would otherwise not be offered. And because that mutation could have come from his mother just as easily as his father, the discovery often triggers a conversation about testing other family members, both male and female, for the same variant. Sisters and daughters of a man found to carry a BRCA2 mutation may themselves face elevated breast and ovarian cancer risk, turning a prostate cancer diagnosis into actionable information for the entire family.
Collecting a Useful Family History
If you are trying to assess your own risk, the single most useful step you can take before any genetic test is to compile a thorough family cancer history from both sides. Many families have only a hazy sense of what their relatives were diagnosed with, especially on the maternal side when it comes to prostate cancer. Here is what to ask about and document:
- Paternal relatives: Father, brothers, paternal grandfather, paternal uncles. Note prostate cancer specifically, including age at diagnosis and whether it was aggressive.
- Maternal relatives: Mother, sisters, maternal grandmother, maternal aunts. Note breast cancer, ovarian cancer, and pancreatic cancer, including age at diagnosis.
- Both sides: Colon cancer, endometrial cancer, and any cancer diagnosed unusually young (before 50). These can flag Lynch syndrome.
- Ashkenazi Jewish heritage: BRCA mutations are more common in this population, making family history collection especially important.
A first-degree relative with prostate cancer on your father’s side roughly doubles the odds of high-grade disease, while breast cancer in a first-degree relative on your mother’s side raises those odds by about 30 percent.11European Urology. Defining the Impact of Family History on Detection of High-grade Prostate Cancer in a Large Multi-institutional Cohort Both are clinically meaningful. Bringing a written family history to your doctor or a genetic counselor makes risk assessment far more precise than relying on memory during an appointment, and it ensures that the maternal side of the ledger does not get left blank.