Doctors warn cancers are going undiagnosed amid COVID-19 pandemic. Here’s what you can do to decrease the risk.

Amidst the COVID-19 pandemic, doctors are concerned that the prolonged shutdowns and stay-at-home orders critical in combating the novel coronavirus may have had dire consequences on early cancer diagnosis and treatment.

Now, a new study finds that new diagnoses for six common cancers, including breast and colon cancer, significantly decreased during the peak of the pandemic.

When comparing the number of weekly cancers diagnosed before and during the pandemic, "there was a 46% decrease in diagnosis of the six common cancer types we looked at, which included breast, colorectal, lung, pancreatic, gastric and esophageal cancers,” said Dr. Harvey Kaufman, the study's co-author and director of the health trends research program at Quest Diagnostics.

Researchers observed the weekly counts of first-time tests for patients associated with six cancers at Quest Diagnostics from Jan. 1, 2018, to April 18, 2020. The drop in diagnoses from March to mid-April is consistent with previous reports and are likely a result of the preventative measures taken at the outset of the pandemic to mitigate the spread of COVID-19, including delaying elective procedures and allocating health care resources for treating COVID-19 patients.

In fact, at the beginning of the pandemic, The American Society of Clinical Oncology recommended decreasing clinic visits and postponing cancer screening to "reduce patient contact with health care facilities."

Experts say that the potential consequences of these delayed diagnoses could have negative consequences for patients.

"The decline clearly represents a delay in making the diagnoses and delays matter with cancer," said Dr. Craig Bunnell, chief medical officer of the Dana-Farber Cancer Institute.

According to Kaufman, delays in cancer screening and diagnosis could lead to patients getting treatment at more advanced stages of their disease, which ultimately increases the risk of complications.

"When cancer screenings and resulting cancer diagnoses are postponed, some of these cancers are likely to later be identified at more advanced stages, which will result in poorer outcomes and even increased death rates," he said.

Experts say monitor for symptoms and signs of cancers

While we still continue to combat COVID-19 and adhere to the public health guidance of staying at home as much as possible and practicing social distancing outside, experts say that continuing to monitor for symptoms and signs of different types of cancers should not be overlooked, whether you’re at home or planning to go to the doctor.

"Recommendations for cancer screening depend on a variety of factors, including someone's age, gender, and family and personal history," said Bunnell. "People should consult their doctors, as they normally would, regarding the most appropriate screening tests for them, but they should not defer those tests unless they have first discussed that with their doctors."

He added, “We need to safely perform these diagnostic tests and the public needs to not think of them as optional. Their lives could depend on them."

With hospitals open, it's imperative patients come in for appointments, doctors say.

“Now that hospitals and clinics are reopening, it is important for patients to continue receiving their health screenings and examinations,” said Dr. Marjon Vatanchi, a board-certified dermatologist with the department of dermatology at Brown University.

The only people who may have to push back appointments, she explained, are those who have strict orders from their doctors to stay at home, like high risk populations or people with compromised immune systems.

Be your own health advocate

Doctors also say that you can serve as your own health advocate when it comes to catching cancer early. Even at home you can be on the lookout for any changes in your body that may be early signs of cancer.

Breast cancer: The American College of Obstetrics and Gynecologists and U.S. Preventive Services Task Force recommends that women routinely check their own breasts and notify their doctors about any changes in shape, masses, changes in discharge from the nipples, or redness, which may be signs of breast cancer.

Skin cancer: When it comes to skin cancer, Vatanchi recommends that everyone do their own monthly skin checks. "Americans can do entire body mole checks at home with a family member checking their back. If there is anything suspicious, then immediately call your dermatologist for a skin check and possible biopsy," she said.

Vatanchi also said to be on the lookout for any suspicious skin changes like "moles that are asymmetrical, have abnormal borders, colors beyond a brown monotone, diameter greater than the end of a pencil eraser, and moles that have changed recently."

Make healthy choices: According to the Centers for Disease Control and Prevention, you can also reduce your risk of cancer by making healthy choices like maintaining a healthy diet and weight, avoiding tobacco, limiting the amount of alcohol you drink and protecting your skin. Use the prolonged time at home now to take on healthier habits that you and your whole family will benefit from.

Keep scheduled appointments: These steps, however, do not substitute a visit to the doctor. It is important to keep up with the recommended cancer screenings and routine checkups with your doctor. Due to COVID-19, many doctors now even offer virtual appointments and staying on track with your appointments can be critical in cancer treatment.

"COVID-19 is a serious threat but cancer isn't going anywhere and needs to be caught and treated early," said Dr. Jeffrey Drebin, chair of the department of surgery at Memorial Sloan Kettering Cancer Center.

Alexis E. Carrington, M.D., is a dermatology research fellow at the University of California, Davis in Sacramento, California, and a contributor to the ABC News Medical Unit. Eden David, who studied neuroscience at Columbia University and is matriculating to Icahn School of Medicine at Mount Sinai later this year, is a member of the ABC News Medical Unit.

Contributing physicians Dr. L. Nedda Dastmalchi and Dr. Molly Stout.