• People cannot smell cancer, but research has assessed certain odors with cancer growth.
  • Chemotherapy treatments can cause noticeable odors.
  • Some chemotherapy medications can also change a person’s sense of smell.

Is there an odor?

When it comes to cancer, early detection can save lives. This is why researchers around the world are working to find new ways to detect cancer before it has the chance to spread.

One interesting avenue of research concerns the smells associated with cancer that the human nose can’t necessarily detect. Researchers are looking to canines, hoping to make use of their superior olfactory talents.

In a 2008 study, researchers taught a dog to differentiate between types and grades of ovarian tumors versus healthy samples. In controlled experiments, the study authors found that their trained dogs were very reliable at sniffing out ovarian cancers.

However, they didn’t think dogs could be used in clinical practice. They noted that a variety of influences could interfere with the task and affect accuracy.

A 2010 study using dogs found that cancer does have a specific scent. What causes that smell isn’t clear, but it may have something to do with polyamines. Polyamines are molecules linked to cell growth, proliferation, and differentiation. Cancer raises polyamine levels, and they do have a distinct odor.

Researchers in this study also found that cancer-specific chemicals might circulate throughout the body. They hope to use this knowledge to advance early detection of colorectal cancer.

Using an electronic nose, researchers have been able to detect prostate cancer from urine smell print profiles.

These studies, and others like them, are a promising area of cancer research. It’s still in its infancy, though. At this time, scent isn’t a reliable screening tool for cancer.

People aren’t able to smell cancer, but you can smell some symptoms associated with cancer.

One example would be an ulcerating tumor. Ulcerating tumors are rare. If you have one, it’s quite possible it will have an unpleasant odor. The odor would be the result of dead or necrotic tissue or of bacteria within the wound.

If you have a bad odor coming from an ulcerating tumor, see your doctor. A course of antibiotics may be able to clear it up. They may also have to remove dead tissue from the area. It’s important to keep the area clean as possible — and moist but not wet.

Dogs may be able to detect certain smells associated with cancer, but humans can detect some smells, too. Usually, those smells have less to do with cancer and more to do with the treatment for cancer.

Powerful chemotherapy drugs can give your urine a strong or unpleasant odor. It might be even worse if you’re dehydrated. A foul odor and dark-colored urine could mean that you have a urinary tract infection (UTI).

Another side effect of chemotherapy is dry mouth. The powerful chemotherapy drugs can cause changes to cells on your gums, tongue, and the insides of your cheeks. This can cause mouth sores, bleeding gums, and tongue irritation. All of these things can lead to bad breath.

You may also develop bad breath from the nausea and vomiting associated with chemotherapy.

If you think your cancer treatment is causing you to have an unpleasant odor, you can try the following:

  • Eat your fruits and veggies to help detoxify your system. The fiber will also help keep your bowel movements regular.
  • Drink lots of water so that your urine is light in color. Hydration minimizes the strong odor when you urinate, aids in digestion, and replenishes fluids after you perspire.
  • If you have a UTI, your doctor will likely prescribe antibiotics. Take them as directed.
  • Exercise based on how much exercise your doctor says is optimal. A good workout that produces sweat is one way to let toxins escape from your body.
  • Indulge yourself in a bath. It can help rid your body of sweat and medicinal smells and make you feel fresh and clean.
  • Change your sheets and blankets often. They can start to smell bad from perspiration, lotions, and medicines.
  • Be extra vigilant about mouth hygiene during chemotherapy to help prevent bad breath. It’s important to brush and floss regularly, but go easy on the floss if your gums bleed.
  • Tell your doctor if you’re frequently vomiting. Prescription anti-nausea medications may be able to cut down on or eliminate vomiting, which contributes to bad breath.

Chemotherapy drugs have an odor. Some of them have a stronger odor than others. That odor may seem to follow you around because your own sense of smell is more sensitive than it normally would be. Other people may not be aware of an odor.

Some chemotherapy drugs can alter your own sense of smell. Certain aromas you used to enjoy, like your favorite foods, may now be quite objectionable. This may affect your appetite and lead to weight loss. Your sense of smell should return to its normal state within a month or two after your last chemotherapy treatment.

Don’t hesitate to speak to your oncology team about your concerns. They may be able to recommend medication or lifestyle changes to help you feel more at ease and eliminate any discomfort.

Any smells that occur due to chemotherapy generally start to clear up after your last treatment.