Long-term outcome of pT1a-b, cN0 breast cancer without axillary dissection or staging: a prospective observational study of 1543 women

BACKGROUND

The implementation of screening programmes in Sweden during the mid-1990s increased the number of small node-negative breast cancers. In this era before staging by sentinel node biopsy, routine axillary dissection for staging of early breast cancer was questioned owing to the increased morbidity and lack of perceived benefit. The long-term risk of axillary recurrence when axillary staging is omitted remains unclear.

METHODS

This prospective observational multicentre cohort study included Swedish women diagnosed with breast cancer between 1997 and 2002. The patients had clinically node-negative, pT1a-b, grade I-II tumours. No axillary staging or dissection was performed. The primary outcome was ipsilateral axillary recurrence and survival.

RESULTS

A total of 1543 patients were included. Breast-conserving surgery (BCS) was performed in 94·0 per cent and the rest underwent mastectomy. After surgery, 58·1 per cent of the women received adjuvant radiotherapy, 11·9 per cent adjuvant endocrine therapy and 31·5 per cent did not receive any adjuvant treatment. After a median follow-up of 15·5 years, 6·4 per cent developed contralateral breast cancer and 16·5 per cent experienced a recurrence. The first recurrence was local in 116, regional in 47 and distant in 59 patients. The breast cancer-specific survival rate was 93·7 per cent after 15 years. There were no differences in overall or breast cancer-specific survival between patients who received adjuvant radiotherapy and those who did not. Only 3·0 per cent of patients had an axillary recurrence, which was isolated in only 1·0 per cent.

CONCLUSION

Axillary surgery can safely be omitted in patients with low-grade, T1a-b, cN0 breast cancers. This large prospective cohort with 15-year follow-up had a very low incidence of axillary recurrences and high breast cancer-specific survival rate.

Abstract P2-08-05: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Jaraj D, Ahlgren J, Arnesson L-G, Einbeigi Z, Höijer J, Klintman M, Malmström P, Vikhe Patil E, Sund M, Fredriksson I, Bergh J, Pettersson A. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-08-05.

No clear effect of postoperative radiotherapy on survival of breast cancer patients with one to three positive nodes: a population-based study

BACKGROUND

In published radiotherapy trials, the failure rate in the control arm among patients with one to three positive nodes is high compared with that seen with modern adjuvant treatments. Therefore, the generalizability of the results has been questioned. The aim of the present study was to compare relative survival in breast cancer patients between two Swedish regions with screening mammography programs and adjuvant treatment guidelines similar with the exception of the indication of radiotherapy for patients with one to three positive nodes.

PATIENTS AND METHODS

Between 1989 and 2006, breast cancer patients were managed very similarly in the west and southeast regions, except for indication for postoperative radiotherapy. In patients with one to three positive nodes, postmastectomy radiotherapy was generally given in the southeast region (89% of all cases) and generally not given in the west region (15% of all cases). For patients with one to three positive nodes who underwent breast-conserving surgery, patients in the west region had breast radiotherapy only, while patients in the southeast region had both breast and lymph nodes irradiated.

RESULTS

The 10-year relative survival for patients with one to three positive lymph nodes was 78% in the west region and 77% in the southeast region (P = 0.12). Separate analyses depending on type of surgery, as well as number of examined nodes, also revealed similar relative survival.

CONCLUSION

Locoregional postoperative radiotherapy has well-known side-effects, but in this population-based study, there was little or no influence of this type of radiotherapy on survival when one to three lymph nodes were involved.

Mammography casting-type calcification and risk of local recurrence in DCIS: analyses from a randomised study

BACKGROUND

We studied the association between mammographic calcifications and local recurrence in the ipsilateral breast.

METHODS

Case-cohort study within a randomised trial of radiotherapy in breast conservation for ductal cancer in situ of the breast (SweDCIS). We studied mammograms from cases with an ipsilateral breast event (IBE) and from a subcohort randomly sampled at baseline. Lesions were classified as a density without calcifications, architectural distortion, powdery, crushed stone-like or casting-type calcifications.

RESULTS

Calcifications representing necrosis were found predominantly in younger women. Women with crushed stone or casting-type microcalcifications had higher histopathological grade and more extensive disease. The relative risk (RR) of a new IBE comparing those with casting-type calcifications to those without calcifications was 2.10 (95% confidence interval (CI) 0.92-4.80). This risk was confined to in situ recurrences; the RR of an IBE associated with casting-type calcifications on the mammogram adjusted for age and disease extent was 16.4 (95% CI 2.20-140).

CONCLUSION

Mammographic appearance of ductal carcinoma in situ of the breast is prognostic for the risk of an in situ IBE and may also be an indicator of responsiveness to RT in younger women.

Histopathological risk factors for ipsilateral breast events after breast conserving treatment for ductal carcinoma in situ of the breast – Results from the Swedish randomised trial

AIM

The primary aims were to study risk factors for an ipsilateral breast event (IBE) after sector resection for ductal carcinoma in situ of the breast (DCIS) in a trial comparing adjuvant radiotherapy to no therapy and to assess predictive factors for response to radiotherapy. Secondary aims were to analyse reproducibility of the histopathological evaluation and to estimate correctness of diagnosis in the trial.

SETTING

A randomised trial in Sweden (the SweDCIS trial), including 1046 women with a median of 5.2 years of follow-up in a population, offered routine mammographic screening.

METHODS

A case-cohort design with a total of 161 cases of IBE (42 of those being members of the subcohort) and 284 sampled for the sub-cohort. Ninety five percent of the participants' slides could be retrieved and were re-evaluated by three experienced pathologists.

RESULTS

Low nuclear grade (NG 1-2) and absence of necrosis halves the risk of IBE in both irradiated and non-irradiated patients. Lesion size, margins of excision and age at diagnosis did not modify these associations. The presence of necrosis modified the effect of radiotherapy: relative risk was 0.40 with necrosis present and 0.07 with necrosis absent (p-value for interaction 0.068). In all subsets of prognostic factors, radiotherapy conferred a substantial benefit. The risk factors for in situ and invasive IBE were similar. The agreement between pathologists was moderate (kappa=0.486). Correctness of diagnosis in the subcohort of SweDCIS was 84.8%.

CONCLUSION

Although nuclear grade and necrosis carry prognostic information, we could not define a group with very low risk after sector resection alone. Radiotherapy has a protective effect in all substrata of risk factors studied. The interaction between the presence of necrosis and radiotherapy is a clinically and biologically relevant research area.

Risk factors for local recurrence after breast-conserving surgery

BACKGROUND

It is not clear whether risk factors for local recurrence after breast-conserving surgery differ in women having surgery for in situ or invasive cancer. Furthermore, the Nottingham Prognostic Index (NPI) and Nottingham Histological Grade (NHG) have been little studied as determinants of local recurrence risk.

METHOD

In a case-control study (491 cases and 1098 controls) nested within a cohort of 7502 women who had surgery for in situ or invasive cancer of the breast, patient characteristics, tumour characteristics and treatment-related variables were evaluated as risk factors for local recurrence.

RESULTS

Multivariate conditional logistic regression analyses showed that age below 40 years, tumour multicentricity and an unclear or unknown surgical margin were significant risk factors for local recurrence. Radiotherapy to the breast and adjuvant hormone therapy were protective. Cancer in situ was not associated with a higher risk of local recurrence than invasive cancer (odds ratio 1.0, 95 per cent confidence interval 0.8 to 1.3). NHG and NPI were not helpful in determining risk of local recurrence.

CONCLUSION

Margin status, age, tumour multicentricity, and use of radiotherapy and adjuvant hormone therapy were important determinants of risk of local recurrence. With the exception of surgical margin, variables related to the quality of surgical management did not predict risk of local recurrence.

Local recurrence in the breast after conservative surgery--a study of prognosis and prognostic factors in 391 women

In a population-based cohort of 6613 women with invasive breast cancer, who had breast-conserving surgery between 1981 and 1990, 391 recurrences in the operated breast were identified. The main aim of this study was to examine the prognosis and prognostic factors in different subgroups of local recurrences, characterised by the time to recurrence, location of recurrence and previously given radiotherapy. The median follow-up for women who had a local recurrence was 7.9 years. The life-table estimates for breast cancer-specific survival in women with local recurrences were 84.5% (standard error (S.E.) 1.8) at 5 years and 70.9% (S.E. 2.7) at 10 years. The risk of breast cancer death was highest among women who had an early (<or=2 years) recurrence in the same quadrant as the primary tumour, with a breast cancer-specific survival of 67.9% (S.E. 4.8) at 5 years and 56.0% (S.E. 5.9) at 10 years. There was a statistically significant difference in the probability of breast cancer-specific survival, as measured from the recurrence, between women who initially did or did not receive radiotherapy (P=0.0123). However, when measured from primary treatment, there was no significant difference, indicating that the difference in prognosis could be due to a lead-time bias. Independent prognostic factors for breast cancer-specific survival in women with local recurrences were time to local recurrence and the Nottingham Prognostic Index (NPI).

Consequences of axillary recurrence after conservative breast surgery

BACKGROUND

The aim was to study the incidence, time course and prognosis of patients who developed axillary recurrence after breast-conserving surgery, and to evaluate possible risk factors for axillary recurrence and prognostic factors after axillary recurrence.

METHODS

In a population-based cohort of 6613 women with invasive breast cancer who had breast-conserving surgery between 1981 and 1990, 92 recurrences in the ipsilateral axilla were identified. Risk factors for axillary recurrence were studied in a case-control study nested in the cohort, and late survival was documented in the women with axillary recurrence.

RESULTS

The overall risk of axillary recurrence was 1.0 per cent at 5 years and 1.7 per cent at 10 years. The risk of axillary recurrence increased with tumour size (P = 0.033) and was highest in younger women (odds ratio (OR) 3.9 for women aged less than 40 years compared with those aged 50-59 years). Radiotherapy to the breast reduced the risk of axillary recurrence (OR 0.1 (95 per cent confidence interval 0.1 to 0.4)). The breast cancer-specific survival rate after axillary recurrence, as measured from primary treatment, was 78.0 per cent at 5 years and 52.3 per cent at 10 years. Tumour size and node status had a statistically significant effect on death from breast cancer.

CONCLUSION

Axillary recurrence is rare, although more common in younger women with large tumours. Radiotherapy to the breast was protective. Tumour size and node status were the most important prognostic factors in women with axillary recurrence.

Time trends in the results of breast conservation in 4694 women

In a population-based cohort of 4694 women with invasive breast cancer, operated upon with breast conserving surgery (BCS) in 1981--1990 and followed through to 1997, we studied how this technique had been adopted into clinical practice, especially with reference to the use of radiotherapy (RT). Our main aim was to see whether there was a drift in the risk of local recurrence and breast cancer death over time. During the 30,151 person-years of observation in the cohort, there were 582 local recurrences, 456 breast cancer deaths and 438 deaths due to other causes. Postoperative RT was given to 70.2%, but usage increased over the period. The women not receiving RT were mostly elderly, but also in women <70 years, 20.4% did not receive RT. The risk for local recurrence after RT were 7.6 and 17.8% at 5 and 10 years, respectively. Without RT, more than 30% had a local recurrence at 10 years. Thus, the choice not to irradiate failed to target women at a low risk. In a multivariate Cox analysis taking tumour size, nodal status, age at operation and RT into account, there was a trend for a higher risk of local recurrence in the later time period, relative hazard 1.5 (95% confidence interval (CI) 1.0--2.1). Corrected survival was 93.3 and 85.2% at 5 and 10 years, respectively.

Omitting axillary surgery for low-risk breast cancer patients--a Swedish prospective cohort study

The effects of mammography screening are a decrease in the sizes of tumours and a shift in stage. Very few small breast cancers (< or = 10 mm) have lymph node metastases when screening-detected, the rate being as low as 7%. Axillary clearance is not necessary for all such small tumours. A Swedish prospective cohort study, scheduled for 1500 patients, is being launched, where axillary surgery is omitted for screening-detected breast cancers of < or = 10 mm showing Elston grade I or II/and/or S-phase < or = 10%. Axillary surgery, with the associated disadvantages, will not be performed in 970 women out of 1000 expecting an axillary recurrence rate of 3%. Nordic breast cancer centres are welcome to join the study, which has already recruited around 500 patients.

Tumour characteristics and survival in patients with invasive interval breast cancer classified according to mammographic findings at the latest screening: a comparison of true interval and missed interval cancers

The aim of this study was to investigate whether different mammographic categories of interval cancer classified according to findings at the latest screening are associated with different distributions of prognostic factors or with different survival rates. The series consisted of all patients with invasive interval cancer detected from May 1978 to August 1995 (n = 544). The tumours were evaluated with regard to age, radiological category, interval between the latest screen and diagnosis and tumour characteristics at the time of diagnosis. We investigated possible relationships between the survival rate of patients with interval cancer and the interval between the latest screen and diagnosis, tumour characteristics and radiological category of the interval tumours. The study focused on comparison of patients with true interval and missed interval cancer. Women with mammographically occult tumours were younger than those in the other radiological categories. Comparisons of true interval cancers with overlooked or misinterpreted tumours showed equal distributions of age, tumour size, TNM stage and lymph node status. The overlooked or misinterpreted tumours showed significantly higher proportions of grade-I tumours (22 vs 11 %), tumours with low S-phase fraction (SPF; 44 vs 24 %) and oestrogen receptor (ER) positive tumours (72 vs 57 %). However, analyses of survival rates disclosed no clear differences between the two radiological categories. Radiological category and interval between the latest screen and diagnosis were not genuine predictors of the prognosis in patients with invasive interval breast cancer. No certain prognostic difference existed between true interval cancers and overlooked or misinterpreted interval breast cancers, despite higher proportions of grade-I tumours, ER positive tumours and tumours with low SPF in the latter group.

Interval cancers and cancers in non-attenders in the Ostergötland Mammographic Screening Programme. Duration between screening and diagnosis, S-phase fraction and distant recurrence

The study was based on a population mammographic screening programme for women aged 40-74 years. Metastatic potential was analysed in 843 invasive breast cancers with regard to mode of detection and a number of prognostic factors. There was a higher metastatic capacity in clinically detected cases, but multivariate analyses showed that neither the mode of detection (hazard rate ratio of distant recurrence RR = 1.39, 95% CI 0.78-2.46 interval cancers and RR = 1.6, 95% CI 0.76-3.36 non-attenders) nor the duration between screening and diagnosis for true interval cancers (RR = 0.47, 95% CI 0.16-1.35 in tumours detected later than one year after screening) were independent prognostic factors. A correlation was found between metastatic potential and the SPF (RR = 2.94, 95% CI 1.57-5.50 in tumours with a high SPF), the oestrogen receptor status and the tumour stage. In conclusion, interval cancers intrinsically are not different from other breast cancers with equivalent characteristics; the duration between screening and diagnosis in interval cancers was not clearly correlated to the prognosis, but the S-phase fraction was a powerful predictor of prognosis.

Histopathology grading in small breast cancers < or = 10 mm--results from an area with mammography screening

Histopathological malignancy grading using the Bloom-Richardson classification of ductal cancers was performed for 248 invasive ductal breast cancers < or = 10 mm operated 1978-1985. There were significantly more grade 1 lesions in the prevalence screening round. Grade 3 was correlated with aneuploidy, higher S-phase (SPF), and more receptor negative tumours. There were also significantly more positive lymph nodes in grade 3 lesions, 18% compared to 5% and 12% respectively for grades 1 and 2 (p < 0.05). In life table analysis for survival, when the high risk group of grade 3 lesions was compared to the grade 1 and 2 lesions combined, five-year disease-free survival was 84.6% vs. 99.1% (p < 0.001). With good training and care from the pathologist, malignancy grading seems useful for prognostication of eventual recurrence and death. In tumours 10 mm or smaller only grade 3 lesions need to be included in follow-up systems and should probably have adjuvant treatment. Malignancy grading is especially good in small ductal breast cancers where grading can always be performed while other prognostic determinations are hampered by shortage of material. Lymph node positivity is also low in this group.

Diagnostic outcome of repeated mammography screening

Mammographic screening for breast cancer within health service routines was evaluated for the years 1987-1992, with special focus on repeated screening during 1989-1992. The overall attendance rate by women aged 40 to 74 years was 82.8%. During 1989-1992 malignancy was found in 2.6/1000 screened women, giving a 87.4% positive predictive rate at surgery and 95.9% efficiency. Among women aged > or = 45 years, the positive predictive rate was > 94%. Fine-needle aspiration (FNA) biopsy showed invasive cancers in 84% and highly suspected cancer in another 15%; 60% of the lesions were nonpalpable. For first-time (prevalence) screening (1987-1988) the positive predictive rate was 86% and the malignancy yield 6.4/1000. In women aged 40-44 years there were few surgical referrals (1.6%), but the positive predictive rate at surgery was only 48.3%, indicating diagnostic difficulties in young women. The median size of all invasive cancers was 12 mm: 84% were classified as pT1, and 23% had lymph node involvement. Stage II disease was found in 27% of all malignancies. The use of FNA in the diagnostic workup for breast cancer screening is of crucial importance to the maintenance of high positive predictive rates at surgery. Moreover, regular analysis is important even when mammographic screening is incorporated into the routine work of health services.

Recurrence-free survival in patients with small breast cancer. An analysis of cancers 10 mm or less detected clinically and by screening

OBJECTIVE

To evaluate survival of women with small breast cancers (10 mm or less in diameter) in a series almost unaffected by adjuvant medical treatment.

DESIGN

Prospective study from a population who were randomly allocated to be screened by mammography.

SETTING

University Hospital.

SUBJECTS

324 patients with breast cancers 10 mm or less in diameter who were operated on between 1978-85 (230 detected by screening, 21 interval cases and 73 from the control group).

MAIN OUTCOME MEASURES

Recurrence free survival, recurrence rate, and breast cancer mortality alone and in relation to node involvement during a median follow up of 7 years (range 4 months-12.5 years).

RESULTS

Survival without distant metastases in life table analyses was 98.7% in 254 node negative cases and 79.3% in 30 node positive cases (p < 0.001). For the whole series survival without distant recurrence was 96.8%. There was no significant difference in recurrence free survival between cancers detected by screening and those detected clinically. Lymph nodes were involved in 9% of the 221 detected by screening compared with 20% of the 89 detected clinically (p < 0.03).

CONCLUSION

There was a very low risk of recurrence in small node negative breast cancers (irrespective of the method of detection) indicating that adjuvant treatment may not be necessary for patients with small node negative breast tumours. The good prognosis of these patients also implies that the need for follow up programmes must be discussed because they are probably unnecessary.

Prediction of axillary lymph node metastases in a screened breast cancer population. South-East Sweden Breast Cancer Group

To define a subgroup of patients, in whom axillary dissection could be omitted, we analysed the frequency of pathologically confirmed lymph node metastases depending on tumour size, hormonal receptors, DNA ploidy, S-phase fraction (SPF), and clinical nodal status among 1,145 patients with stage I-II breast cancer from an area with ongoing screening. Clinical nodal status and tumour size were strongly correlated to pathological nodal status. Also SPF > 10% was strongly correlated to node positivity in univariate analysis. In multivariate analysis there was still a significant correlation among cases with tumour size < or = 20 mm. In conclusion, patients with clinically negative nodal status, and tumour size < or = 20 mm and < or = 10 mm had pathologically positive nodes in 25% and 15% of cases respectively. The addition of SPF did not lower these figures significantly since small tumours with high SPF are few.

Hormone receptors, ploidy and proliferation rate in breast cancers up to 10 mm

A total of 191 malignant mammary lesions of 10 mm or less in diameter have been analysed with regard to hormone receptor content (107 of 179) and ploidy (112 of 191) in a repeated mammography screening population (second to fourth screening round). Forty-eight per cent were diploid and 68% oestrogen receptor-positive. Mean proliferation rate, calculated as S-phase fraction (SPF), was 6.2 +/- 5.0. Significantly lower SPF was observed in diploid tumours. In very small tumours (less than or equal to 5 mm) SPF was higher as was the fraction of receptor-negative tumours. Among these small cancers a hypothetical high-risk group with SPF greater than or equal to 10% and receptor-negativity will contain 7% of the patients. If SPF and receptor content are chosen as prognostic factors, the latter patients may be a group suitable for adjuvant therapy in treatment schedules.

Follow-up of two treatment modalities for ductal cancer in situ of the breast

In a mammography screening programme for the early detection of breast cancer 66 cases of ductal cancer in situ of the breast (DCIS) were diagnosed between 1978 and 1984 and prospectively followed up. In the beginning of the study period, DCIS was treated by mastectomy without axillary clearance but sector resection has been performed increasingly. Since 1982 the latter procedure has become standard treatment. Radical resection was confirmed by specimen X-ray and histopathological examination of whole organ sections. No postoperative radiotherapy was given. Twenty-eight women had mastectomy and 38 had sector resection. The median follow-up times were 77 and 60 months respectively. In the mastectomy group postoperative monitoring did not reveal any local recurrence but one contralateral new invasive cancer was discovered. In the sector resection group five recurrences were found. Three of the latter were new cases of DCIS and two appeared as small invasive cancers (stage I). Mastectomy will cure ductal cancer in situ but has a greater morbidity. Sector resection has been established as the method of choice in stage I invasive cancer and is probably also safe in DCIS. The possible beneficial effect of postoperative local radiotherapy after sector resection for DCIS is currently being analysed in a randomized trial which started in Sweden in 1987.

Surgical biopsy of non-palpable mammary lesions. Technique and results

In a randomized controlled trial with mammographic screening for early detection of breast cancer, 314 non-palpable breast lesions were examined by open biopsy between 1978 and 1983. These biopsies were performed after the lesions had been indicated by the hooked wire technique. In 185 cases the findings turned out to be benign while 129 proved to be malignant. Satisfactory initial biopsies were achieved in 95% of the cases. A model for the management of mammary lesions found in such a screening programme is described and some difficulties are discussed.