Rates and prevalence of cervical cancer in the United States, especially among older women, are likely higher than what current statistics indicate. Past analyses did not account for all influential factors, a new study suggests.

The study, published in the peer-reviewed journal Cancer, argues that professionals studying the prevalence of cervical cancer in the United States have been severely misled by what was accepted as fact, simply due to the inclusion of extraneous data - namely the inclusion of women who have had a hysterectomy.

According to the American Cancer Society (ACS), women between the ages of 40 and 44 are at the highest risk of cervical cancer, with 15.6 women being diagnosed with the disease per every 100,000. This is why current ACS guidelines recommend that women should be screened for cervical cancer every three years after they turn 21, and then every five years after they turn 55. ACS notes that women need not continue with screenings after they turn 65 if regular screenings prior to then did not indicate an elevated risk of cancer.

However, a new analysis of US cervical cancer diagnoses data suggests that women past the age of 65 may in fact be the most at risk of the disease, with nearly 19 in every 100,000 women developing the cancer.

How was this overlooked? According to the study, current ACS statistics include women with total hysterectomies, skewing the data. Total hysterectomies involve the removal of the uterus and cervix. Of course, women who have undergone this procedure cannot be diagnosed with cervical cancer, and should not have been included in the national statistics, researchers advocate.

When analysts removed total hysterectomy prevalence from the "at risk " cervical cancer population, the researchers found that the 65-and-over age group was the most severely affected, resulting in a rise of incidents rates from a mere 11.7 per 100,000 women to 18.6 per 100,000 women.

Alarmingly, the overall trend of cervical cancer risk also changed with this tweak. Originally it was assumed that cervical cancer rates peaked around the age of 40 and fell off by age 65. Now the researchers found that the overall incidents rates actually increased with age, peaking between the age 65 and 69.

These numbers indicate that the understanding of cervical cancer patterns in the US was completely wrong, and it was this incorrect understanding that led to the creation of current screening guidelines.

"Given the high and not declining rate of cervical cancer in women over the age of 60 to 65 years... risk and screening guidelines for cervical cancer in older women may need to be reconsidered," the study concludes.

The study was published in Cancer on May 12.