The operative management of screen-detected breast cancers

European Code against Cancer, 4th Edition: Cancer screening

In order to update the previous version of the European Code against Cancer and formulate evidence-based recommendations, a systematic search of the literature was performed according to the methodology agreed by the Code Working Groups. Based on the review, the 4th edition of the European Code against Cancer recommends: "Take part in organized cancer screening programmes for: Bowel cancer (men and women); Breast cancer (women); Cervical cancer (women)." Organized screening programs are preferable because they provide better conditions to ensure that the Guidelines for Quality Assurance in Screening are followed in order to achieve the greatest benefit with the least harm. Screening is recommended only for those cancers where a demonstrated life-saving effect substantially outweighs the potential harm of examining very large numbers of people who may otherwise never have, or suffer from, these cancers, and when an adequate quality of the screening is achieved. EU citizens are recommended to participate in cancer screening each time an invitation from the national or regional screening program is received and after having read the information materials provided and carefully considered the potential benefits and harms of screening. Screening programs in the European Union vary with respect to the age groups invited and to the interval between invitations, depending on each country's cancer burden, local resources, and the type of screening test used For colorectal cancer, most programs in the EU invite men and women starting at the age of 50-60 years, and from then on every 2 years if the screening test is the guaiac-based fecal occult blood test or fecal immunochemical test, or every 10 years or more if the screening test is flexible sigmoidoscopy or total colonoscopy. Most programs continue sending invitations to screening up to the age of 70-75 years. For breast cancer, most programs in the EU invite women starting at the age of 50 years, and not before the age of 40 years, and from then on every 2 years until the age of 70-75 years. For cervical cancer, if cytology (Pap) testing is used for screening, most programs in the EU invite women starting at the age of 25-30 years and from then on every 3 or 5 years. If human papillomavirus testing is used for screening, most women are invited starting at the age of 35 years (usually not before age 30 years) and from then on every 5 years or more. Irrespective of the test used, women continue participating in screening until the age of 60 or 65 years, and continue beyond this age unless the most recent test results are normal.

Influence of mammographic screening on trends in breast-conserving surgery in Ireland

Debate exists about the influence of screening on breast cancer surgery. We compared rates and odds of mastectomy and breast-conserving surgery (BCS) during 1994-1999 between Northern Ireland, which has had organized mammographic screening (age group 50-64) since 1993, and the Republic of Ireland, where large-scale screening did not begin until 2000. Trends in BCS were similar in both populations: significant increases in BCS rates for age groups 20-49 and, especially, 50-64, and significant increases in mastectomy rates for age group 65+ only. Use of BCS among surgical patients was significantly higher in Northern Ireland (46%) than the Republic of Ireland (35%) and, in Northern Ireland, was significantly higher in age group 50-64 than other age groups. Geographic and age-related variations were substantially, but not wholly, explained by tumour characteristics and screen-detection status. Among Northern Ireland women aged 50-64, BCS use among screen-detected cases, even after adjustment for tumour characteristics, was 40-50% higher and increased more rapidly during 1994-1999 than among other cases. However, trends in BCS in Northern Ireland were not explained by changes in screen-detection status or tumour characteristics. Our findings are consistent with expectations that mammographic screening, together with modern treatment guidelines, should lead to reduced use of mastectomy and increased (proportional) use of BCS. But similar trends occurred in the absence of large-scale screening (in the Republic of Ireland), and surgical treatment of screen-detected cases did not reflect tumour characteristics alone.

Assessing the effectiveness of a mammography screening service

BACKGROUND

Trials have shown that mammography screening reduces mortality and probably decreases morbidity related to breast cancer.

METHODS

We assessed whether the major mammography service in Western Australia (BreastScreen WA) is likely to reduce mortality by comparing prognostic variables between screen-detected and other cases of breast cancer diagnosed in 1999. We assessed likely reductions in morbidity by comparing treatments received by these two groups. To confirm mortality and morbidity reduction, we also compared prognostic variables and treatments with targets. Information on demographic variables, tumour characteristics at presentation and treatments were collected from medical records for all incident cases of breast cancer in Western Australia in 1999. We matched cases with the Western Australian Cancer Registry records to determine which cases had been detected by BreastScreen WA.

RESULTS

BreastScreen WA achieved the targets for mortality reduction. Tumours detected by BreastScreen WA were smaller in size, less likely to have vascular invasion, of lower histological grade and were more likely to be ductal carcinoma in situ alone without invasive carcinoma. Oestrogen receptor status was more likely to be positive, the difference in progesterone status was not significant, and lymph node involvement tended to be lower. BreastScreen WA patients were treated more often with local therapy and less often with systemic therapy, and the proportion of patients treated with breast-conserving surgery was close to the target for minimizing morbidity in breast cancer.

CONCLUSION

Mammographic detection of breast cancer by BreastScreen WA is associated with reduced breast cancer morbidity and a more favourable prognosis.

Breast carcinoma diagnosis, treatment, and prognosis before and after the introduction of mass mammographic screening

BACKGROUND

The introduction of breast carcinoma screening leads to early detection and is believed to reduce mortality and increase the proportion of patients for whom breast-conserving surgery is possible.

METHODS

In 1992, a population-based mammographic screening program was introduced in the Dutch city of Tilburg and its surroundings; the program achieved total coverage in 1996. The authors examined the effects of this screening program by investigating disease stage, treatment, and survival among women diagnosed with breast carcinoma at a teaching hospital in Tilburg during the periods 1985-1991 and 1992-1999.

RESULTS

Between January 1, 1985, and December 31, 1999, 1400 patients were diagnosed with breast carcinoma. Among patients ages 50-69 years, the proportion of TNM Stage I breast carcinoma increased from 24% in 1985-1991 to 45% in 1992-1999 (P<0.001). The proportion of patients age <50 years with invasive breast carcinoma who underwent breast-conserving surgery decreased from 45% to 33% (P=0.011). Among patients ages 50-69 years, the overall survival rate during the period from 1992 to 1999 was significantly greater than the corresponding rate during the period from 1985 to 1991 (P=0.0009). Even after adjustments were made for tumor stage and patient age, a slight reduction in mortality risk was observed in this age group. No difference in stage distribution or prognosis was found among patients age <50 years or among patients age > or =70 years. Of the 168 invasive malignancies found in patients ages 50-69 years between 1997 and 1999, 68 (40%) were detected by the screening program, 47 (28%) were interval malignancies, and 53 (32%) were detected in nonparticipants or in women who did not participate in 1 or more screening rounds. Patients with screen-detected tumors had a much more favorable prognosis than did patients with interval malignancies (P=0.0018) or patients with clinically detected breast carcinoma (P<0.0001).

CONCLUSIONS

Between 1992 and 1999, after the introduction of breast carcinoma screening, improved prognosis and more favorable tumor stage were observed among patients ages 50-69 years. Even after the screening program was fully implemented in 1996, the majority of invasive malignancies still were detected between screening rounds or in patients who did not participate in the program.

The introduction of mammographical screening has had little effect on the trend in breast-conserving surgery: a population-based study in Southeast Netherlands

In addition to reducing breast cancer mortality, breast cancer screening programmes are expected to increase the proportion of patients who can undergo breast-conserving surgery. Trends in the use of breast-conserving surgery (BCS) in Southeast Netherlands between 1990 and 1998 were studied in relation to the gradual introduction of mammographical screening for women 50-69 years of age between 1992 and 1996. The characteristics of the tumours detected by the screening programme or outside of the programme were compared, to see whether this might clarify the observed trends. In the period 1990-1998, 4788 patients were diagnosed with invasive, operable breast cancer, of whom 2341 were 50-69 years of age. Although the screening programme resulted in a larger proportion of patients with small tumours and more favourable tumour characteristics, no increase was observed in the use of BCS for patients 50-69 years of age in the period 1990-1998 (64% in 1990 and 1998). Patients with a screening-detected tumour, however, were more likely to undergo breast conservation compared with those presenting clinically (68% versus 54%; P<0.0001). In conclusion, no increase in the proportion of breast-conserving surgical procedures was observed in Southeast Netherlands among patients 50-69 years of age in the period 1990-1998, during the introduction of mass mammographical screening for this group. Screening, however, resulted in a larger proportion of patients with small tumours with more favourable characteristics, who are better candidates for breast conservation.