NEW YORK (Reuters Health) -
A new study shows that some
women with breast cancer fail to complete their radiation
therapy, pointing to a need to help more women to see their
treatment through to the end.

Researchers found that of 24,500 U.S. women diagnosed with
breast cancer between 1992 and 2002, after surgery, radiation
therapy was completed by 87 percent.

While that figure is “reassuring,” the researchers report
in the journal Cancer, the 13 percent of patients who did not
complete therapy still represents a fairly large number of
women.

This is of concern because radiation treatment after breast
cancer surgery lowers the chances of cancer recurrence, note
Dr. Tomasz P. Srokowski of the University of Texas M.D.
Anderson Cancer Center in Houston and colleagues.

The researchers based their findings on data from a
government cancer- surveillance system. They focused on the
records of 24,510 women 66 years of age or older who underwent
surgery and radiation for early- to mid- stage breast cancer —
cancer that had not spread to distant sites in the body.

In general, the study found, women who were treated with a
mastectomy were less likely to complete radiation therapy than
those who'd received less-extensive surgery. Black women were
less likely to complete therapy than were white women — 16
percent did not have a full course of radiation, versus just
over 12 percent of white women.

In the case of mastectomy patients, the researchers
speculate that after such radical surgery, some women — as
well as their doctors — may place less importance on follow-up
radiation, compared with those who only have the tumor removed.

But the reason for the racial discrepancy is not clear,
according to Srokowski's team. Factors like income and
education level did not appear to explain the difference.

Overall, women who did not complete radiation had a
slightly higher risk of cancer recurrence over the next 5
years. However, the vast majority of both completers and
non-completers — more than 95 percent in both cases — were
recurrence-free during that time.

Still, the researchers say, more studies should look into
why some women fail to complete their breast cancer treatment,
and what should be done about it.

There was some evidence in the current study that the
situation is improving, however. Women who had been diagnosed
in more-recent years were more likely than others to complete
post-surgery radiation.

This, according to Srokowski's team, may reflect
improvements in radiation therapy that have reduced side
effects, as well as greater awareness of the potential benefits
of post-surgery radiation.

SOURCE: Cancer, July 1, 2008.