Inequalities in Diagnosis of Common Cancers

Becky McCall

November 13, 2012

LONDON, United Kingdom — Inequalities in sex, socioeconomic status, and age influence the stage at which cancer is diagnosed, according to a study published online November 12 in the Annals of Oncology.

If these inequalities were substantially reduced, 5600 patients would benefit from earlier diagnoses.

In fact, in 1 of 9 patients with 7 common cancers, advanced-stage diagnosis could be prevented, said lead author Georgios Lyratzopoulos, MD, clinical senior research associate at the University of Cambridge, United Kingdom. Patients diagnosed with prostate cancer, breast cancer, lung cancer, or melanoma would benefit most from fewer inequalities, he explained.

The study was conducted in collaboration with researchers from the Eastern Cancer Registration and Information Centre (ECRIC), and the findings are particularly pertinent to the National Awareness and Early Diagnosis Initiative (NAEDI), which is currently being run by the government and patient charities in the United Kingdom.

This initiative was sparked by cancer mortality statistics that showed that the United Kingdom lags behind many European countries. Part of the problem lies in the fact that cancer is diagnosed at a later stage, highlighting the need to improve diagnose cancer at an earlier stage.

Sir Mike Richards, MD, national clinical director for cancer at the Department of Health, said that this study "clearly demonstrates the value of collecting staging data on cancer patients at a population level. It shows that significantly more patients could be diagnosed at an early stage (and thus have better survival) if inequalities by age, gender, or deprivation were to be eliminated."

Ten Cancer Types

The researchers analyzed 10 types of cancer: female breast, lung, colon, rectal, prostate, renal, bladder, ovarian, and endometrial cancer, and melanoma. These represent two thirds of all cancers diagnosed in England.

The researchers were motivated by a need to build on the benefits of primary cancer prevention measures, which only have the potential to reduce about 45% of cancers. They conducted this study of different cancers to better understand the variation in risk for advanced-stage diagnosis, Dr. Lyratzopoulos told Medscape Medical News.

Previous studies of this dataset have looked at the effect of age on stage at diagnosis for lung and breast cancers.

In patients from the East of England diagnosed with any of the 10 cancers from 2006 to 2010, stage at diagnosis was analyzed. Stage information was available for 88,657 of 98,942 tumors (89.6%). The cancers analyzed represented 67% of new cancer diagnoses in England in 2009 and 57% of all cancer deaths.

Potential Lives Saved

For 7 cancers, evidence shows that stage at diagnosis is affected by inequalities. The researchers estimate that there are approximately 146,000 diagnoses of these cancers each year, and that 52,000 (36%) of these diagnoses are at an advanced stage.

If all sex, socioeconomic, and age inequalities were eliminated, there would be around 5600 fewer cases diagnosed at an advanced stage annually in England, the researchers report. "This would represent an approximate 11% reduction in the advanced-stage cases of the 7 cancers for which there was evidence of potential gain in early stage diagnosis," they write.

"Prostate, melanoma, and endometrial cancer have the largest proportional early diagnosis gains," they add. Among the 5600 advanced-stage diagnoses prevented, 2000 would be in prostate cancer, 1000 would be in breast cancer, 1300 would be in lung cancer, and 700 would be in melanoma.

Diagnosis for Different Cancers

Strong evidence suggests that women are less likely to be diagnosed with 1 of the 10 cancers at an advanced stage than men (P = .003), and that as socioeconomic status decreases, diagnosis at an advanced stage is more likely (P < .001). In general, older people are more likely to be diagnosed at an advanced stage than younger people (P < .001).

Specifically, women were less likely to be diagnosed with melanoma at an advanced stage than men (odds ratio [OR], 0.68; 95% confidence interval [CI], 0.57 to 0.81; P < .001); the same was true for lung cancer (OR, 0.88; 95% CI, 0.81 to 0.96; P = .003).

The most deprived patients were more likely to be diagnosed at an advanced stage if they had melanoma, breast cancer, endometrial cancer, or prostate cancer

However, the oldest patients with bladder cancer were less likely to be diagnosed at an advanced stage than patients 65 to 69 years of age (P = .002); the same was true for lung cancer (P < .001) and renal cancer (P = .009).

"Regarding lung and renal cancer specifically, one hypothesis is that when patients are older and have a greater number of morbid conditions, they may be exposed to more tests. For example, with lung cancer, many of these patients have COPD and have regular lung x-rays." Dr. Lyratzopoulos added that similar mechanisms might be at play for kidney cancers because the use of abdominal imaging scans increases with age.

Differences in Healthcare-Seeking Behavior

"For cancers for which there is an excess risk of advanced-stage diagnosis with older age (such as breast, prostate, endometrial, and melanoma), we believe different patient perceptions of cancer symptoms and differences in healthcare-seeking behavior may be responsible for social differences in stage at diagnosis," explained Dr. Lyratzopoulos. "These cancers are easy to diagnose once presented to the doctor, therefore, by deduction, the only explanation for the inequalities is a delay in seeking medical attention after symptom onset," he said.

Dr. Lyratzopoulos said that in addition to awareness and symptom appraisal, psychological and emotional barriers might lead to a later stage at diagnosis; people might ignore the signs when they know there might be risk for cancer.

Jane Wardle, PhD, director of the Health Behaviour Research Centre at Cancer Research UK, was asked to comment on the study by Medscape Medical News. She said that the sociodemographic differences in cancer survival are a continuing embarrassment to the principles of health equality, even within universal healthcare systems such as the British National Health Service.

In particular, she noted, there were greater inequalities by age and socioeconomic status in some of the easier-to-diagnose cancers, "whereas those more difficult to diagnose showed less inequalities." The researcher's explanation that patient delay in presentation affects stage at diagnosis "is consistent with results of our work showing demographic differences in awareness of classic warning signs," she said.

"Together, these results indicate that improving awareness of symptoms and willingness to visit the GP for persistent 'bodily changes' could help to reduce cancer inequalities," Dr. Wardle concluded.

Dr. Lyratzopoulos pointed out that their findings provide a roadmap for better targeting of initiatives, such as the NAEDI, and interventions to help diagnose cancer at an earlier stage. "Such initiatives need to be focused and tailored to different groups of individuals, and have a cancer-specific focus," he said.

He noted that there were no substantial social differences related to stage at diagnosis for 3 cancers: ovarian, colon, and rectal cancers. In spite of this, the researchers suggest a cautious approach regarding interventions and campaigns.

"Awareness campaigns about the symptoms of bowel and ovarian cancer have been launched relatively recently, and future research should establish their effectiveness," noted senior coauthor David Greenberg, PhD, from ECRIC.

"Avoiding a patchy dissemination of awareness messages among different social groups is important to prevent future inequalities in early diagnosis and for such campaigns to have the maximum impact," he added.

The study was supported by the National Institute for Health Research and ECRIC. Dr. Lyratzopoulos and Dr. Greenberg have disclosed no relevant financial relationships. Dr. Wardle sits on the steering committee for the National Awareness and Early Diagnosis Initiative.

Ann Oncol. Published online November 12, 2012. Abstract