New study reveals big disparity between countries in breast conservation rates


Hamburg, Germany: The rates of conservation surgery for breast cancer vary hugely between countries, delegates at the 4th European Breast Cancer Conference heard today (Friday 19 March).

In France 72% of patients had breast conservation surgery but in Poland it was only 2%. The figures come from an analysis of surgical techniques used in an international trial of adjuvant treatment among 4,700 women with early breast cancer in 37 countries the Intergroup Exemestane Study. However, Professor Jacek Jassem, the cancer specialist who compiled and analysed the statistics, believes the results are representative of treatments generally in those countries.

Professor Jassem, who is head of the Department of Oncology and Radiotherapy at the Medical University of Gdansk in Poland, and the conference chairman, said that despite breast conserving surgery being widely accepted as a valuable alternative to mastectomy, the latter continues to be used as a main surgical approach.

"It is somewhat surprising," he said, "and I would consider it both a medical and a sociological phenomenon."

In the 37 countries overall, more than half the patients underwent mastectomy, nearly 40% had wide local excision of their tumour and 10% had some other form of breast conserving surgery.

The mastectomy rate was highest in central and eastern Europe at 77%. The USA had the second highest rate of mastectomy with 56%, western and northern Europe averaged 46%, southern Europe 42% and Australia and New Zealand 34%.

The difference in surgery was despite the main clinical and therapeutic characteristics of the patients being well balanced in the two arms of the randomised global study, which was comparing the safety and efficacy of postoperative tamoxifen vs sequential tamoxifen and exemestane in postmenopausal women with operable breast cancer. The surgery involved was dependent on tumour characteristics, but otherwise had been left to the discretion of the investigators, and all curative surgical procedures had been allowed.

To reduce the risk of any bias, Professor Jassem analysed in detail only the 10 countries that had contributed a minimum of 150 patients drawn from several centres in each country.

The mastectomy rates were:
* France 28%
* UK 31%
* Belgium 37%
* Italy 41%
* Germany 43%
* Switzerland 47%
* The Netherlands 48%
* USA 56%
* Spain 66%
* Poland 98%

Professor Jassem, who is the past chairman of the EORTC's Breast Cancer Group, said he had been prompted to carry out the analysis by one done two years ago by the ATAC research team when it was comparing anastrozole with tamoxifen.

"The results of the two are similar so I would consider this situation typical for a general population of breast cancer patients," he said.

Professor Jassem concluded that there were a number of explanations for the variation. One major factor was that the tumours might be more advanced when they were diagnosed in those countries with higher mastectomy rates. "Early detection is strictly related to screening programmes and in countries with no nationwide screening programmes the cancer is likely to be more advanced on average at diagnosis. We can't take tradition and surgeons' and patients' attitudes into account in the analysis but this may be another factor. Finally, in some countries, access to radiotherapy may be an issue."
Abstract no: 362 (16.00 hrs Friday 19 March, Hall 1)

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