This study evaluated the use of complementary medicine (CAM) such as vitamins, minerals, and herbs by breast cancer patients undergoing adjuvant radiotherapy. The study found that 27% of 879 patients used some form of CAM during radiation treatment. The most commonly used CAM were magnesium (30% of CAM users) and selenium (16% of CAM users). The study found no significant differences in short-term side effects or disease recurrence rates between CAM users and non-users or among the most common types of CAM used. However, the selenium group showed a higher rate of local and systemic failure that warrants further investigation in a larger group of patients.

1. Complementary medicine use during
adjuvant radiotherapy in breast cancer
R. Bücker | G. Jaenke | U. Schäfer
Klinikum Lippe GmbH | Radiation Oncology Department
Rintelner Straße 85 | 32657 Lemgo | Germany | Phone +49 (0) 52 61 . 26 - 46 21 | www.klinikum-lippe.de
Background
Complementary medicine (CAM) is used widely in cancer patients, mostly in palliati-
ve treatment regimens or during chemotherapy. In contrast, the use of CAM during
curative Radiotherapy (RT) is less frequent. The aim of this study was to evaluate
the influence of CAM with regard to toxicity and recurrence after postoperative radi-
otherapy for breast cancer.
Material and methods
Between 2010 and 2013 all patients intended for adjuvant radiotherapy for breast
cancer received a questionnaire concerning the use of CAM e. g. Vitamins, trace
elements, enzymes, natural herbs etc. (yes/no) and if yes what kinds. Radiotherapy
was applied with 50.4 Gy to the whole breast and a Boost of 10.8 Gy in 6.5 weeks.
6 weeks after radiotherapy the side effects were analyzed according RTOG grading.
Follow up for progression rates was done yearly until January 2018. To determine
whether there is a significant difference between the expected frequencies and the
observed frequencies, a chi-squared test was used. All events were collected until
January 2018.
Results
A total number of 879 patients with breast cancer completed the questionnaire,
641/879 (73 %) patients did not take any complementary medicine (non CAM) and
238/879 (27 %) patients took CAM. There were almost 40 different products men-
tioned.
137/238 (57.6 %) patients took one CAM product, 86/238 (36.1 %) two, and
15/238 (6.3 %) more than two CAM products.
The most common were magnesium (Mg) in 71/238 (30 %) patients and selenium
in 38/238 patients (16 %), for overview see pie chart 1.
Pie Chart 1: Distribution of all CAMs mentioned in the questionnaires (multiple entries possible up to a
maximum of 3 products). Products specified up to a frequency of 1 %.
The RT side effects (Dermatitis RTOG grade 0, I, II, III/IV) 6 weeks after completion of RT
were as follows: in the non CAM group 53 % grade 0, 41 % grade I, and 6 % grade II, 0 %
grade III/IV. And in the CAM group 54 %, 38 %, 8 %, and 0.4 % respectively. The corre-
sponding side effects for the group taking magnesium were 51 % 42 %, 6 % and 1 % and
for the selenium group 47 %, 47 %, 5 % and 0 % (bar chart 2). There was no significant
difference in side effects between the non CAM and CAM patients, respectively magnesi-
um and selenium.
Conclusion
In this cohort, 27 % of patients used CAM during adjuvant radiotherapy of breast cancer. The most commonly used product is magnesium followed by selenium.
A significant influence of CAM on subacute RT side effects or disease progression could not be identified. However, the higher rate of local and systemic failure in
the selenium group appears remarkable. Therefore, this analysis will be continued with a higher number of patients.
The sum of all registered disease progression (0 years – 5 years) were in the non CAM
group 6.4 %, in the CAM group 6.3 %, in the magnesium group 5.6 % and in the selenium
group 7.9 %, no significant difference could be detected between all groups.
Bar Chart 1: Bar chart: Distribution of subacute side effects 6 weeks after the end of radiotherapy,
separated for non CAM, CAM, magnesium and selenium
Bar Chart 2: Bar chart: Relative distribution of recurrences divided into local, regional, systemic and
secondary cancers, separated for non CAM, CAM, magnesium and selenium
Table 1: Level of significance for the bar charts in graphic 33 (vs = versus)