Mammographic findings after breast conservation therapy

Time to development and imaging features of new calcifications in the treated breast after breast-conserving therapy

OBJECTIVE

The purpose of our study was to analyze the time to development, malignancy rate, location, and mammographic features of new calcifications in the treated breast after breast-conserving therapy (BCT).

MATERIALS AND METHODS

In this HIPAA-complaint, IRB-approved retrospective study, we reviewed the records of patients treated with BCT at our institution with breast-conserving surgery performed between January 1, 2009 and December 31, 2010. A total of 735 breasts in 732 women were included in our study cohort. Factors analyzed included rate of development of new calcifications, malignancy rate of new calcifications, the time between completion of radiation therapy and development of new calcifications, imaging features of new calcifications, and location of the new calcifications in relation to the primary malignancy.

RESULTS

During follow-up, new calcifications developed in 155 of the 735 treated breasts (21.1%) and 155 of the 732 women (21.2%). After excluding two cases that were lost to follow-up, the malignancy rate of new calcifications was 5.2% (8/153; 95% CI: 2.3% to 10.0%). The median time to development of the benign calcifications was 27 months (range, 2 to 91 months) and of the malignant calcifications was 41 months (range, 11 to 57 months). Of the 20 (13.1%) cases of new calcifications categorized as BI-RADS 3 (probably benign), all were benign on follow-up (19 cases) or on biopsy (1 case). Of the 51 BI-RADS 4 (suspicious) cases, 8 (16%) were biopsy-proven malignant. The malignancy rate was the highest in fine pleomorphic 100% (1/1), followed by amorphous 17%, (5/29), coarse heterogeneous 8% (2/26) and typically benign 0 (0/97) calcifications (p < 0.0001). The malignancy rate was 1.5% (2/137) for new calcifications within the lumpectomy site vs. 37.5% (6/16) for new calcifications outside the lumpectomy site (p < 0.0001) and was 3.4% (5/147) for new calcifications at or within the same quadrant as the lumpectomy site vs. 50.0% (3/6) for new calcifications in a different quadrant from the lumpectomy site (p=0.002).

CONCLUSION

Most new calcifications that developed in the treated breast after BCT were benign. Evaluation of morphology and distribution of those calcifications is imperative. New calcifications in the treated breast outside the lumpectomy site are more likely to be malignant and should be viewed with greater suspicion. Benign calcifications developed earlier than malignant calcifications, but the time courses overlapped.

Oncoplastic breast surgery: A guide to good practice

Oncoplastic Breast Surgery has become standard of care in the management of Breast Cancer patients. These guidelines written by an Expert Advisory Group; convened by the Association of Breast Surgery (ABS) and the British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS), are designed to provide all members of the breast cancer multidisciplinary team (MDT) with guidance on the best breast surgical oncoplastic and reconstructive practice at each stage of a patient's journey, based on current evidence. It is hoped they will also be of benefit to the wide range of professionals and service commissioners who are involved in this area of clinical practice.

Palpable Masses after Mastectomy: Differentiating Benign Postoperative Findings from Recurrent Disease

Due to postoperative changes, imaging evaluation of patients with palpable masses after mastectomy can be challenging. There is considerable overlap between the imaging characteristics of recurrent disease and benign postoperative findings in patients with or without breast reconstruction. US is the initial modality of choice for evaluating palpable masses in most patients after mastectomy. In cases where US findings are not classic, however, other modalities are useful in problem solving, including both mammography and MRI. It is imperative that radiologists are educated about benign and malignant imaging characteristics, further workup considerations, and appropriate management. In cases where findings are not characteristic across multiple imaging modalities, biopsy may be warranted.

Supplemental Breast US Screening in Women with a Personal History of Breast Cancer: A Matched Cohort Study

Background There is limited research on supplemental screening breast US in women with a personal history of breast cancer (PHBC). Purpose To compare the performance of supplemental screening breast US in women with and women without a PHBC by using a matched cohort. Materials and Methods Consecutive asymptomatic women who underwent radiologist-performed supplemental breast US and mammography between January 2013 and December 2013 at a tertiary referral university hospital were retrospectively identified. Inclusion criteria were negative or benign findings at mammography, follow-up data for at least 1 year, first cancer stage of 0 to II in women with a PHBC, and incidence screening in women without a PHBC. The two groups were matched 1:1 according to age and breast density. Performance measures were compared with McNemar test, generalized estimating equation, or penalized likelihood logistic regression. Results A total of 3226 women with a PHBC were matched with 3226 women without a PHBC (mean age ± standard deviation, 52 years ± 9; mammographic breast density, fatty in 603 and dense in 2623). Fourteen cancers (six screen-detected, eight interval cancers) were found in women with a PHBC and 13 cancers (12 screen-detected, one interval cancer) in women without a PHBC. Supplemental US in women with a PHBC compared with women without a PHBC showed lower sensitivity (43% [95% confidence interval {CI}: 18%, 71%; six of 14 cancers] vs 92% [95% CI: 64%, 100%; 12 of 13 cancers]; P = .03), higher interval cancer rates (2.5 [95% CI: 1.1, 4.9; eight of 3226 women] vs 0.3 [95% CI: 0, 1.7; one of 3226 women] per 1000; P = .02), and higher specificity (92.8% [95% CI: 91.9%, 93.7%; 2982 of 3212 women] vs 89.3% [95% CI: 88.2%, 90.4%; 2870 of 3213 women]; P < .001), respectively. Conclusion Supplemental US screening in women with a personal history of breast cancer had lower sensitivity and higher interval cancer rate but higher specificity relative to women without a personal history of breast cancer. © RSNA, 2020 Online supplemental material is available for this article. See also the editorial by Lee and Lee in this issue.

Spectrum of Multimodality Findings in Post-surgical Breast Cancer Imaging

BACKGROUND

Breast cancer is the commonest cancer affecting Malaysian women, accounting for an estimated 30% of all new cancer diagnosed annually. Improvements in breast cancer management have increased the breast cancer survival rate in Malaysia. Clinical and radiological surveillance of the treated breast is vital, as early detection of recurrence improves patient's survival rate.

DISCUSSION

As surgery and radiotherapy alter the appearance of the breasts, distinguishing between recurrence and benign post-surgical changes can be challenging radiologically due to overlapping features. Despite this, differentiation between these two entities is usually possible by recognizing characteristic features of post-treatment sequelae and the evolution of the appearance of the conservatively treated breast by comparing interval findings on serial studies.

CONCLUSION

This pictorial review aims to describe the typical and unusual features of post-treated breasts in the multimodality imaging workup of an established breast care centre in a teaching hospital in Malaysia.

Digital Mammographic Features of Breast Cancer Recurrences and Benign Lesions Mimicking Malignancy Following Breast-Conserving Surgery and Radiation Therapy

Mammography after breast-conserving surgery and radiation therapy is an important tool for followup. Early diagnosis of local recurrence enables prompt treatment decisions, which may affect patient prognosis. For complicated post-treatment changes, radiologists sometimes have difficulties in interpreting follow-up mammography. Fat necrosis, dystrophic calcifications, suture calcification features, breast edema, seroma and distorted breast are benign changes related to treatment. These findings may mimic or hide tumor recurrence making it difficult to diagnose recurrences or prevent inappropriate biopsies. Recurrent tumors in follow-up mammography show several typical findings such as increasing asymmetric density, enlarging mass, reappearance of breast edema, and micro-calcifications. The purpose of this pictorial review is to demonstrate and discuss mammographic findings of recurrent tumors and important post-treatment changes that may mimic benign or malignant lesions, also using breast ultrasound images or breast magnetic resonance images. Recognizing post-treatment changes may help radiologists to more effectively identify candidates for suspected local recurrences.

Breast imaging surveillance after curative treatment for primary non-metastasised breast cancer in non-high-risk women: a systematic review

OBJECTIVES

The article summarises the available guidelines on breast imaging surveillance after curative treatment for locoregional breast cancer.

METHODS

A systematic review of practice guidelines published from 1 January 2007 to 1 January 2017 was performed according to PRISMA methodology. The search was conducted for the EMBASE, MEDLINE, Cochrane and Centre for Reviews and Dissemination databases. On 8 July 2018, all included guidelines were updated to the most recent version.

RESULTS

Twenty-one guidelines originating from 18 publishing bodies matched criteria. Publishing bodies consisted of seven governmental institutions, nine medical societies and two mixed collaborations. Publishing boards consisted of six radiological, four oncological, and 11 multidisciplinary teams. Annual bilateral mammography surveillance after breast-conserving therapy was recommended by 17/18 (94.4%) publishing bodies. Annual contralateral mammography surveillance after mastectomy was recommended by 13/18 (72.2%) publishing bodies. Routine use of digital breast tomosynthesis was recommended by 1/18 (5.6%) publishing bodies. Routine breast ultrasound surveillance was recommended by 2/18 (11.1%), deemed optional by 4/18 (22.2%) and not supported by 8/18 (44.4%) publishing bodies. Routine breast magnetic resonance imaging (MRI) surveillance was not recommended by 16/18 (88.9%) publishing bodies, although 6/18 (33.3%) specified subgroups for systematic MRI surveillance.

CONCLUSIONS

Annual mammography is currently the 'gold standard' for breast imaging surveillance. The role of digital breast tomosynthesis (DBT) remains to be further investigated. Most guidelines do not recommend routine breast ultrasound or MRI surveillance, unless indicated by additional risk factors.

Imaging of the treated breast post breast conservation surgery/oncoplasty: Pictorial review

Mammographic appearance of the normal breast is altered in the post-operative setting. It is essential to be aware of the normal findings as well as to identify features of recurrent disease with particular emphasis on radiological-pathological concordance. Digital breast tomosynthesis and volumetric breast density add incremental value in this clinical setting. We present a pictorial review of various cases to illustrate normal post-operative findings as well as mammographic features suspicious for recurrent disease.

Assessment and Management of Challenging BI-RADS Category 3 Mammographic Lesions

Breast Imaging Reporting and Data System (BI-RADS) category 3 lesions are probably benign by definition and are recommended for short-interval follow-up after a diagnostic workup has been completed. Although the original lexicon-derived BI-RADS category 3 definition applied to lesions without prior imaging studies (when stability could not be determined), in clinical practice, many lesions with prior images may be assigned to BI-RADS category 3. Although the BI-RADS fifth edition specifically delineates lesions that are appropriate for categorization as probably benign, it also specifies that the interpreting radiologist may use his or her discretion and experience to justify a "watchful waiting" approach for lesions that do not meet established criteria. Examples of such lesions include evolving masses or calcifications suggestive of prior trauma and instances when stability cannot be ascertained because of image quality. Although interval change is an important feature of malignancy, many benign lesions also change over time; thus, use of prior imaging studies and ongoing imaging surveillance to demonstrate the evolution of a probably benign lesion is justified. Some examples of common pitfalls associated with inappropriate BI-RADS category 3 assessment include failure to use proper BI-RADS descriptors, failure to perform a complete diagnostic workup, and overreliance on negative ultrasonographic findings. When appropriately used, short-interval follow-up saves many patients from undergoing biopsy of benign lesions, without decreasing the rate of cancer detection. (©)RSNA, 2016.

Advancements in Imaging Technology for Detection and Diagnosis of Palpable Breast Masses

Breast cancer is the most commonly diagnosed cancer among women worldwide and the most common cause of cancer death in women. The most common presentation of breast cancer is the presence of a palpable mass, whether noted by the patient during breast self-examination or noted during clinical breast examination. There are a variety of imaging modalities now available for the evaluation of a palpable abnormality. A thorough understanding of the indications, risks, and benefits can help the clinician guide the patient through an appropriate, comprehensive imaging work up.

Comparison of Mammographic Changes Across Three Different Fractionation Schedules for Early-Stage Breast Cancer

PURPOSE

As the use of hypofractionated breast radiation therapy (RT) increases, so will the need for long-term data on post-RT mammographic changes. The purpose of the present study was to longitudinally compare the incidence of common mammographic sequelae seen after breast conserving surgery and RT in patients treated with accelerated partial breast irradiation (APBI), hypofractionated whole breast irradiation (HWBI), and conventionally fractionated whole breast irradiation (WBI).

METHODS AND MATERIALS

Patients treated with either APBI or HWBI after breast conserving therapy and with ≥3 mammograms of the treated breast were identified. They were matched 1:1 by age ±5 years to patients treated with WBI. The mammograms were evaluated for common post-RT breast findings by a mammographer who was unaware of the treatment. The outcomes were analyzed using a cumulative logistic regression model; P<.05 indicated statistically significance.

RESULTS

Of 89 patients treated with RT from 2006 to 2011, 29 had received APBI, 30 had received HWBI, and 30 had received WBI. Their median age was 60 years (range 33-83). A total of 605 mammograms were evaluated, with a median follow-up of 48 months. The treatment technique did not affect the severity of architectural distortion when the groups were evaluated longitudinally. The likelihood of finding skin thickening decreased with increasing follow-up duration (odds ratio 0.6; P<.001) adjusted for fractionation schemes. No differences were seen with respect to changes in skin thickening, fluid collections, or calcifications among the treatment groups, after adjustment for the follow-up time. The clinical characteristics, including age, race, T stage, and chemotherapy use, were not linked to the likelihood of finding several mammographic phenomena over time.

CONCLUSIONS

Although specific post-treatment imaging findings evolved over time, RT fractionation did not alter the relative incidence or severity of architectural distortion, skin thickening, fluid collections, or calcifications. These findings will be useful to both radiologists and radiation oncologists when counseling patients regarding follow-up studies after RT.

Assessing the impact of radiation-induced changes in soft tissue density ∕ thickness on the study of radiation-induced perfusion changes in the lung and heart

PURPOSE

Abnormalities in single photon emission computed tomography (SPECT) perfusion within the lung and heart are often detected following radiation for tumors in∕around the thorax (e.g., lung cancer or left-sided breast cancer). The presence of SPECT perfusion defects is determined by comparing pre- and post-RT SPECT images. However, RT may increase the density of the soft tissue surrounding the lung∕heart (e.g., chest wall∕breast) that could possibly lead to an "apparent" SPECT perfusion defect due to increased attenuation of emitted photons. Further, increases in tissue effective depth will also increase SPECT photon attenuation and may lead to "apparent" SPECT perfusion defects. The authors herein quantitatively assess the degree of density changes and effective depth in soft tissues following radiation in a series of patients on a prospective clinical study.

METHODS

Patients receiving thoracic RT were enrolled on a prospective clinical study including pre- and post-RT thoracic computed tomography (CT) scans. Using image registration, changes in tissue density and effective depth within the soft tissues were quantified (as absolute change in average CT Hounsfield units, HU, or tissue thickness, cm). Changes in HU and tissue effective depth were considered as a continuous variable. The potential impact of these tissue changes on SPECT images was estimated using simulation data from a female SPECT thorax phantom with varying tissue densities.

RESULTS

Pre- and serial post-RT CT images were quantitatively studied in 23 patients (4 breast cancer, 19 lung cancer). Data were generated from soft tissue regions receiving doses of 20-50 Gy. The average increase in density of the chest was 5 HU (range 46 to -69). The average change in breast density was a decrease of -1 HU (range 13 to -13). There was no apparent dose response in neither the dichotomous nor the continuous analysis. Seventy seven soft tissue contours were created for 19 lung cancer patients. The average change in tissue effective depth was +0.2 cm (range -1.9 to 2.2 cm). The changes in HU represent a <2% average change in tissue density. Based on simulation, the small degree of density and tissue effective depth change is unlikely to yield meaningful changes in either SPECT lung or heart perfusion.

CONCLUSIONS

RT doses of 20-50 Gy can cause up to a 46 HU increase in soft tissue density 6 months post-RT. Post-RT soft tissue effective depth may increase by 2.0 cm. These modest increases in soft tissue density and effective depth are unlikely to be responsible for the perfusion changes seen on post-RT SPECT lung or heart scans. Further, there was no clear dose response of the soft tissue density changes. Ultimately, the authors findings suggest that prior perfusion reports do reflect changes in the physiology of the lungs and heart.

The postconservation breast: part 1, Expected imaging findings

OBJECTIVE

The objectives of this article are to discuss the conventional imaging algorithms after breast-conserving surgery and radiation therapy and to review the expected chronologic imaging appearances of the conservatively treated breast.

CONCLUSION

Imaging the treated breast presents challenges because of its limited compressibility and the overlapping features of benign posttreatment alterations and tumor recurrence. After lumpectomy and radiation therapy, mammographic findings such as breast edema, skin thickening, fluid collections, architectural distortion, and calcifications have characteristic sequences of evolution toward stability. Awareness of these normal chronologic imaging findings for the conservatively treated breast minimizes unnecessary recall from screening and permits early detection of recurrent breast carcinoma.

Mammographic findings after intraoperative radiotherapy of the breast

Intraoperative Radiotherapy (IORT) is a form of accelerated partial breast radiation that has been shown to be equivalent to conventional whole breast external beam radiotherapy (EBRT) in terms of local cancer control. However, questions have been raised about the potential of f IORT to produce breast parenchymal changes that could interfere with mammographic surveillance of cancer recurrence. The purpose of this study was to identify, quantify, and compare the mammographic findings of patients who received IORT and EBRT in a prospective, randomized controlled clinical trial of women with early stage invasive breast cancer undergoing breast conserving therapy between July 2005 and December 2009. Treatment groups were compared with regard to the 1, 2 and 4-year incidence of 6 post-operative mammographic findings: architectural distortion, skin thickening, skin retraction, calcifications, fat necrosis, and mass density. Blinded review of 90 sets of mammograms of 15 IORT and 16 EBRT patients demonstrated a higher incidence of fat necrosis among IORT recipients at years 1, 2, and 4. However, none of the subjects were judged to have suspicious mammogram findings and fat necrosis did not interfere with mammographic interpretation.

Mammographic findings of partial breast irradiation

RATIONALE AND OBJECTIVES

The aim of this study was to determine if patients who underwent partial-breast irradiation followed by segmental mastectomies had fewer mammographic changes on the first post-treatment mammogram than those who underwent segmental mastectomies followed by whole-breast irradiation.

MATERIALS AND METHODS

Subjects enrolled in a study of partial-breast irradiation therapy after segmental mastectomy (intraoperative radiation therapy) plus a random sample of patients who underwent segmental mastectomies followed by conventional whole-breast radiation therapy were identified through the institution's breast cancer database from March 2003 through February 2006. A radiologist specializing in breast imaging reviewed and recorded each patient's pretreatment mammogram for breast density and tumor location and the first post-treatment mammogram, obtained within the first year of treatment, for three common types of mammographic change seen after breast surgery and radiation treatment (breast edema, skin thickening, and surgical scarring), which when severe make it difficult to use mammography for continuing follow-up of the conserved breast. The extent of mammographic change was noted by the radiologist as minimal, moderate, or marked. The data were entered into a database, and statistical analysis was conducted using logistic regression models and chi(2) tests. The effect of breast density on mammographic change was also assessed.

RESULTS

The severity of edema was lower with decreasing breast density (P < .006). There was no apparent effect of breast density on the severity of skin thickening. The extent of surgical scarring decreased as breast density increased (P < .026). Analysis of the data from the cumulative logistic regression models demonstrated that even after controlling for breast density, patients who underwent whole-breast radiation therapy had significantly more edema (P = .003), skin thickening (P = .003), and surgical scarring than those who underwent intraoperative radiation therapy (P < .001).

CONCLUSION

Patients have a higher probability of having fewer post-treatment mammographic changes after partial-breast irradiation followed by segmental mastectomy than after breast conservation surgery followed by whole-breast irradiation.

Tc-99m-methoxy isobutyl isonitrile scintimammography: imaging postexcision biopsy for residual and multifocal breast tumor

OBJECTIVES

The interpretation of mammogram in a postsurgical breast can be extremely complex and difficult because masses, calcifications, and architectural distortion can mimic cancer. Scintimammography has been proposed because it is not affected by these morphological changes and can potentially be used in patients after excision biopsy to assess any residual tumor, other foci of disease (multifocal disease).

MATERIALS AND METHODS

The population comprised of 21 patients (mean age: 47.80 years, median age: 50 years, and age range: 26-77 years) evaluated for suspected residual breast cancer after excision biopsy. All patients received a 740-1000 MBq bolus IV injection of Tc-99m-methoxy isobutyl isonitrile (MIBI) preferably in pedal vein. At 5-10 min after injection, planar images were obtained in prone lateral and supine anterior positions using dual head gamma camera. MIBI uptake was scored as follows: 1 - as normal uptake (compared with contralateral side), 2 - focal low-intense uptake (equivocal), and 3 - focal high-intense uptake (positive). All patients had histopathology for tissue diagnosis.

RESULTS

Of the 21 patients evaluated, scintimammography planar was found true positive in 13 and true negative in six. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 92.85, 85.71, 92.85, 85.71, and 90.47%, respectively (P<0.001). Scintimammography detected 2/2 multifocal disease.

CONCLUSION

In patients after excision biopsy, scintimammography with Tc-99m-MIBI is valuable in assessing residual or multifocal disease. Scintimammography has high positive predictive value and may influence planning further management.

Early mammographic and sonographic findings after intraoperative radiotherapy (IORT) as a boost in patients with breast cancer

The aim of this study was to evaluate mammographic and sonographic changes at the surgical site within the first 2 years after IORT as a boost followed by whole-breast radiotherapy (WBRT), compared with a control group treated with WBRT alone. All patients had breast-conserving surgery for early-stage breast cancer. Group A: n = 27, IORT (20 Gy) followed by WBRT (46 Gy). Group B (control group): n = 27, WBRT alone (56-66 Gy). Mammography: fat necrosis in 14 group A versus four group B patients (P < 0.001); parenchymal scarring classified as unorganized at the last follow-up in 16 vs seven cases, respectively (P = 0.03). Ultrasound: overall number of patients with circumscribed findings 27 vs 18 (P < 0.001); particular hematomas/seromas in 26 vs 13 patients (P < 0.001). Synopsis of mammography and ultrasound: overall postoperative changes were significantly higher classified in group A (P = 0.01), but not judged to have a significantly higher impact on interpretation. Additional diagnostic procedures, due to unclear findings at the surgical site, were performed on four patients of both groups. Within the first 2 years after IORT as a boost, therapy-induced changes at the original tumor site are significantly more pronounced compared with a control group. There is no evidence that the interpretation of findings is complicated after IORT.

MRI in the detection and management of breast cancer

Breast magnetic resonance imaging (MRI) is now at a stage where the evidence is suggesting widespread potential in the management of patients with known or suspected breast cancers. MRI is used as a supplementary tool to complement conventional methods of breast evaluation because it has excellent problem-solving capabilities. Many indications for clinical breast MRI are recognized, including resolving findings on mammography, staging of breast cancer when multiple or bilateral disease is suspected, and detecting the occult primary breast cancer presenting with malignant axillary lymphadenopathy but no detectable lesion on conventional breast examination. There is also encouraging ongoing research evaluating its role for the assessment of patients at high risk of breast cancer, for primary staging of cancers in radiographically dense breasts and for the assessment of response to chemotherapy. This article will review both the technical aspects of performing and interpreting breast MRI, as well as the current and possible future roles of breast MRI, comparing its strengths and weaknesses with conventional imaging.

Magnetic resonance imaging in breast cancer recurrence

PURPOSE

To determine the sensitivity, specificity and accuracy of magnetic resonance imaging (MRI) in detecting breast cancer recurrence.

MATERIALS AND METHODS

Forty women conservatively treated for breast cancer underwent MRI and confirmation on histology and cytology of suspected local recurrence. In these patients both clinical and mammographic/ultrasound features of local recurrence were nonspecific or suspicious. All patients were examined at least 1 year after completion of radiation treatment. Dynamic magnetic resonance imaging was performed with a 1.5 T unit using a dedicated bilateral breast coil. Qualitative and quantitative data were obtained. Statistical analysis was also performed with the Student T-test.

RESULTS

Breast cancer recurrence was confirmed on histology in 22 patients. MRI identified all the 22 breast recurrent cancers. False-positive contrast enhancement was seen in only two patients. In four patients recurrence was classified as multifocal. In one patient the tumor was detected in the contralateral breast. MRI showed 95% accuracy, 100% sensitivity, 88.8% specificity with 5% false-positives and 100% negative predictive value.

CONCLUSION

Dynamic MRI appears a valuable technique for differentiation of post-treatment changes from recurrent carcinoma and for guiding the histological confirmation. Its high negative predictive value may have an impact on follow-up of treated breast.

Detection of breast cancer after biopsy for false-positive screening mammography. An increased risk?

INTRODUCTION

After false-positive screening for breast cancer, women are still at risk of developing breast cancer. In this study the incidence of breast cancer in a group of women who had a false-positive outcome is compared with the expected breast cancer incidence.

METHODS

Follow-up data of 188 women (mean age 58 years) with a false-positive screening result were collected and analysed for breast cancer development. The mean length of follow-up in the study was 7.4 years. The occurrence of breast cancer was compared to the expected incidence of breast cancer in an age-matched control population using figures from the local cancer registration.

RESULTS

The occurrence of breast cancer in the study population (n=7) was not significantly different from the expected incidence of breast cancer in the age-matched control group (n=5).

CONCLUSION

There is no relationship between false-positive findings during breast cancer screening and later development of breast cancer. Patients who do not have an increased risk of developing breast cancer (due to family history) should not be followed-up clinically, but should be returned to the screening programme.