Breast parenchymal patterns: prevalent and incident carcinomas.

Breast parenchymal patterns can be divided into four groups: N1, P1, P2 and DY. Although there is evidence that the P2-DY group favors the development of cancer, the risk classification changes when one considers prevalent vs. incident breast cancers. In a purely incident series, a gradual diminution will be seen in the number of N1-P1 cancer cases and a corresponding rise in cancer patients from the P2-DY group.     

Breast parenchymal patterns: analysis of 332 incident breast carcinomas

A detailed analysis of 332 incident breast carcinomas is presented. The study results indicate that there is validity to the breast parenchymal patterns as an indication of risk for developing breast cancer and that risk is independent of length of follow-up and age of patient. All cases were drawn from a referral-type practice at Hutzel Hospital, Detroit, MI. The cases were compared to controls for computation of relative risk up to and beyond a follow-up period of 48 months. They were also compared to a consecutive series of prevalent breast carcinomas seen at Hutzel Hospital during the 6 years 1975-1980. The extent of disease in the cases described in this report is somewhat more favorable than in a consecutive series of prevalent cancers operated on a Hutzel Hospital. Most breast cancers occur in the P2 breast, a smaller number in the DY, and only 12% in the combined N1P1 type. The conclusions of other investigators regarding parenchymal patterns as risk indicators are reviewed. Particular attention was paid to comparing the length of follow-up and age of patient. There was no diminution of proportions of cases in the P2/N1-P1 or DY/N1-P1 after a 48 month follow-up. There was a significant diminution in the proportion of cases falling into DY/N1-P1 after age 50, and less so in P2/N1-P1. Furthermore, relative risk was unaffected by time or age.     

我国医用诊断X射线工作者1950年～1990年间恶性肿瘤危险分析

目的提供小剂量慢性照射诱发人类恶性肿瘤的证据和有关规律。方法用Ｏ／Ｅ程序分析了我国２４个省、直辖市、自治区２７０１１名医用诊断Ｘ射线工作者和２５７８２名其他科医务人员１９５０～１９９０年间恶性肿瘤发病资料。结果Ｘ射线工作者的恶性肿瘤发病率显著高于对照医务人员（ＲＲ＝１．１，９５％可信限为１．０～１．２）。发病率明显增加的恶性肿瘤是白血病、皮肤癌、妇女乳腺癌、肝癌和食管癌，相对危险分别为：２．３，５．０，１．６，１．３和４．４。白血病危险的增高主要见于１９７０年前开始Ｘ射线工作和开始放射工作时年轻者。结论从Ｘ射线工作者恶性肿瘤的相对危险与工龄、参加Ｘ射线工作时年龄和时期分析表明，Ｘ射线工作者的白血病、皮肤癌和妇女乳腺癌发病率的增加与职业Ｘ射线照射有关     

Mammographic parenchymal patterns and quantitative evaluation of mammographic densities: a case-control study

The classification of breast parenchymal patterns (N1, P1, P2, DY) and the percentage of the breast containing radiographic densities are two highly correlated radiographic measures proposed as predictors of the risk of breast cancer. In this case-control study, 160 cases of breast cancer and 160 matched controls from a mammography referral practice were compared to determine the risk of breast cancer associated with each of these two radiographic measures. The mammographic densities were quantified on caudal projections by means of a compensating polar planimeter. A relative risk estimate of 3.3 (p less than .05) was associated with the P2 + DY patterns compared with the N1 + P1 patterns. Significantly elevated risks of 4.3 to 5.5 also were observed among women whose breasts contained at least 25% mammographic densities, compared with women with less than 25% involvement. These radiographic measures tended to be more predictive of the risk of breast cancer in black women than in white women. Although the precise clinical roles of breast parenchymal patterns and densities have not been defined fully, the results of this study suggest that they are useful in the recognition of women at high risk of breast cancer. We make no claims that the findings of this study are sufficiently developed to be used as a basis for screening strategies.     

Mammographic patterns and risk of breast cancer.

A study of 171 breast cancer cases matched by age and race to asymptomatic controls was undertaken to check Wolfe's assertion [1, 2] that breast cancer risk depends strongly on the mammographic classifications N1, P1, P2, and DY. The classifications were made blindly relative to all variables, including the case-control factor. Distribution of the four categories among the breast cancer patients in this study was consistent with the distribution found by Wolfe. (P = .46). Our age-standardized risk ratio estimates of the categories, relative to N1, are 1.5 for P1, 2.7 for P2, and 7.2 for DY. While not as striking as Wolfe's estimates, the same monotone trend is evident, and the cases and controls differ significantly with respect to the distributions of the four categories (P less than .01).     

The mammographic parenchymal patterns of nulliparous women and women with a family history of breast cancer

One-hundred-and-thirteen mammograms of nulliparous women and 44 mammograms of women with a family history of breast cancer were graded according to Wolfe's parenchymal pattern classification. These were compared to 437 mammograms of women without these risk factors. Mammograms were read by two independent observers in order to evaluate inter- and intra-observer variation. The interobserver variation was reduced from 17% to 5% by combining high risk patterns (P2 and DY) and low risk patterns (N1 and P1). A significantly higher proportion of high risk patterns was found in nulliparous women compared to parous women (P less than 0.01). The proportion of high risk patterns decreased significantly with the number of children (P less than 0.01). Women with a family history of breast cancer had almost the same parenchymal patterns as women without a family history. In conclusion, while nulliparity and family history are recognized risk factors for developing breast cancer, only nulliparity would appear to influence the mammographic parenchymal pattern. This probably reflects the different mechanism by which the two factors affect breast tissue.     

A prospective study of mammographic parenchymal patterns and risk of breast cancer

Breast parenchymal patterns have been assessed by the method of Wolfe in a prospective study in Guernsey. Women with P2 or DY grades had approximately four times the risk of developing breast cancer compared with those with N1 or P1 grades. Age, weight, parity and age at birth of first child are all related to the distribution of mammographic patterns. The combination of these variables with Wolfe grades may identify subsets of the population at very high risk.     

Size, node status and grade of breast tumours: association with mammographic parenchymal patterns

A case-control study was designed to assess the association of mammographic parenchymal patterns with the risk of in-situ and invasive breast cancer. In addition, the relationship between tumour characteristics and mammographic patterns were also investigated. A total of 875 patients with breast cancer were selected and matched with 2601 controls. Mammographic parenchymal patterns of breast tissue were assessed according to Wolfe's classification, and statistical analysis was by conditional logistic regression. Relative to the N1 pattern, the odds ratios of having an invasive breast cancer associated with the P2 and DY patterns were 1.8 and 1.4, respectively. In addition, the odd ratios of having an invasive grade 3 breast cancer associated with the P2 and DY patterns were 2.8 and 3.9, respectively. Relative to the combined N1/P1 pattern, the odd ratios of having a breast cancer smaller than 14 mm, 15–29 mm, or larger than 30 mm associated with the combined high-risk P2/DY pattern (P2 + DY) were 1.2, 1.6, and 2.0, respectively. Finally, women with the P2/DY pattern were twice as likely to have a breast cancer which had already spread to the axillary nodes, compared to women with women with the N1/P1 pattern (odds ratios of 2.1 and 1.4, respectively). Our results confirm previous findings suggesting that mammographic parenchymal patterns may serve as indicators of risk for breast cancer. Our results also suggest that mammographic parenchymal patterns are associated with the stage at which breast cancer is detected. Received: 22 March 1999; Recieved after revision: 22 July 1999; Accepted: 27 July 1999     

Aspects in mammographic screening. Detection,prediction, recurrence and prognosis

Screening mammograms comprising of 32 first round, 10 interval and 32 second round detected cancers and 46 normal were examined by an expert screener, a screening radiologist, a clinical radiologist and a computer-assisted diagnosis (CAD) system. The expert screener, screening radiologist, clinical radiologist and the CAD detected 44, 41, 34 and 37 cancers, respectively, while their respective specificities were 80%, 83%, 100% and 22%. Later, with CAD prompting, the screening and the clinical radiologist detected 1 and 3 additional cancers each with unchanged specificities. Screening mammograms comprising 35 first round, 12 interval and 14 second round detected cancers and 89 normal findings were examined without and with previous mammograms by experienced screeners. Without previous mammograms, the screeners detected 40.3 cancers with a specificity of 87%. With previous mammograms, 37.7 cancers were detected with a 96% specificity. The decrease in sensitivity was not significant but the screeners showed significant increase in specificity. Local recurrences in 303 nonpalpable breast cancers with preoperative localizations and breast conservation therapy were evaluated for needle-caused implant metastasis. A total of 214 percutaneous biopsies were performed. There were 33 local recurrences. Needle-caused seeding or implantation as based on the location of the recurrence in comparison to the needle path in the mammograms was suspected in 3/44 (7%) invasive cancers without radiotherapy. The mammographic characteristics of 317 nonpalpable breast cancers were categorized. Logistic regression showed that the risk ratios for a spiculated mass without calcifications and calcifications alone were 12 and 19 for invasive cancer and ductal cancer in situ (DCIS), respectively. Invasive ductal grade 1, ductal grade 2, lobular and ductal grade 3, had a risk ratio (RR) of 28, 17, 11 and 4.6, respectively, for a spiculated mass without calcifications. DCIS nuclear grade 3 and invasive ductal grade 3 had an RR of 17 and 9.7, respectively, for sole casting calcifications. The eight-year survival of 96 1-9-mm invasive breast cancers were investigated in relation to their mammographic appearance, node status and histologic grade. After a median follow-up of 7 years, 6/96 died from breast cancer: 3/14 had calcifications alone, 2/56 had spiculated masses, 1/12 had rounded mass, 5/78 were node-negative and 1/4 was node-positive. The survival rate was 93%: 77% for the calcifications alone, 95% for spiculated masses, 91% for rounded masses, 92% for node-negative and 75% for node-positive. Calcifications alone and node positivity, each, carried a significantly higher risk of death.     

The effect of hormone replacement therapy on the sensitivity of screening mammograms.

AIM: The use of hormone replacement therapy (HRT) can lead to various changes on the mammogram including increasing density. The object of this study was to assess the effect of HRT on the sensitivity of mammographic screening by comparing HRT usage in women with screen detected breast cancers with HRT usage at the time of screening in women presenting with interval cancers. METHODS: The West of Scotland Breast Screening Programme serves a population of 180,000 women aged 50-64 years old. Between May 1988 and December 1995, 1461 breast cancers were detected by the screening programme in 1441 women over the age of 50 and 372 interval breast cancers presented in 371 women screened between these dates. HRT usage at the time of screening was noted with details of age, postcode and the time between screening and diagnosis in the case of the women with interval cancers. RESULTS: Among women under 65 years old, screened between 1988-1993, 12.3% of women with screen detected cancers and 22.2% of women with interval cancers were using HRT (P<0.001). Further analysis demonstrates that interval cancer rate is related to age as well as HRT use. After adjusting for age at time of screening, deprivation category and year of screening, the relative risk of a woman using HRT having an interval cancer compared with that of a woman not using HRT is 1.79. The relative risk of an interval cancer arising in the first year after screening for a woman on HRT is 2.27. CONCLUSION: The use of HRT and being of an age below 60 years are both risk factors for presenting with an interval cancer after mammographic breast screening. Our results indicate that the use of HRT leads to a decrease in the sensitivity of mammographic screening.     

中国医用诊断X射线工作者1950～1995年恶性肿瘤危险分析

目的：提供职业照射诱发人类恶性肿瘤的证据和评价其危害。方法：用O／E程序分析了我国24省、直辖市、自治区1950－1980年间在职的27011名医用诊断X射线工作者和25782名其他科医务工作人员1950－1995年间的恶性肿瘤发病资料。结果：X射线工作者的恶性肿瘤发病率明显高于对照医务人员，相对危险（RR）为1．2，95％可信限（CI）为1．1－1．3。发病率明显增加的肿瘤是白血病，皮肤癌，女性乳腺癌，肺癌，肝癌，膀胱癌和食管癌，RR分别为：2．2，4．1，1．3，1．2，1．2，1．8和2．7，甲状腺癌的发病率也见增加，R＝1．6，95％（CI）为0．9－2．6，结论：X射线工作者白血病、皮肤癌，女性乳腺癌，可能还有甲状腺癌相对危险的增高与职业X射线的照射有关，当累积剂量达到一定水平时，这些肿瘤的相对危险明显增高。     

Risk-Based Screening Mammography for Women Aged <40: Outcomes From the National Mammography Database

ObjectiveThere is insufficient large-scale evidence for screening mammography in women <40 years at elevated risk. This study compares risk-based screening of women aged 30 to 39 with risk factors versus women aged 40 to 49 without risk factors in the National Mammography Database (NMD).MethodsThis retrospective, HIPAA-compliant, institutional review board–exempt study analyzed data from 150 NMD mammography facilities in 31 states. Patients were stratified by 5-year age intervals, availability of prior mammograms, and specific risk factors for breast cancer: family history of breast cancer, personal history of breast cancer, and dense breasts. Four screening performance metrics were calculated for each age and risk group: recall rate (RR), cancer detection rate (CDR), and positive predictive values for biopsy recommended (PPV₂) and biopsy performed (PPV₃).ResultsData from 5,986,131 screening mammograms performed between January 2008 and December 2015 in 2,647,315 women were evaluated. Overall, mean CDR was 3.69 of 1,000 (95% confidence interval: 3.64-3.74), RR was 9.89% (9.87%-9.92%), PPV₂ was 20.1% (19.9%-20.4%), and PPV₃ was 28.2% (27.0%-28.5%). Women aged 30 to 34 and 35 to 39 had similar CDR, RR, and PPVs, with the presence of the three evaluated risk factors associated with significantly higher CDR. Moreover, compared with a population currently recommended for screening mammography in the United States (aged 40-49 at average risk), incidence screening (at least one prior screening examination) of women aged 30 to 39 with the three evaluated risk factors has similar cancer detection rates and recall rates.DiscussionWomen with one or more of these three specific risk factors likely benefit from screening commencing at age 30 instead of age 40.     

Risk-benefit analysis for mass screening of breast cancer utilizing mammography as a screening test

Incidence of breast cancers in Japanese women is increasing steadily. Mass screening of breast cancer was started in Japan under auspices of Adult Health Promotion Act of the Japanese Government from 1987. As the first screening method, the palpation of breasts is employed at present, but it is expected to be replaced by the mammography. In this report, the risk-benefit analysis is presented between risk of breast carcinogenesis due to radiation and benefit of mass screening of breast cancer. The benefit of mass screening is taken as the net elongation of average life expectancy of women due to survival from breast cancers. The risk of mammography is taken as the net loss of average life expectancy of women due to breast carcinogenesis. In the latter, the latency time and plateau period of radiation carcinogenesis were taken into consideration in the calculation. The results show that the ages at which the benefit and risk become equal are between 30 and 35 years old when dose equivalent of mammography is between 10 and 20 mSv, that are conventionally used. However, the critical age will be reduced to 20 years old if the dose equivalent becomes 1 mSv. Therefore, it is strongly recommended that a low dose mammographic system should be developed in order to achieve 1 mSv for the mass screening of breast cancer of Japanese women. In author's opinion, this is quite feasible by employing a new digital radiography with imaging plate.     

Correlation between breast parenchymal patterns and mammographers' certainty of diagnosis

The density of breast tissue on a mammogram may affect radiologists' diagnostic decisions. To evaluate possible correlations among breast parenchymal pattern and diagnostic confidence, six radiologists classified 655 mammograms as N1, P1, P2, and DY, according to Wolfe's criteria. Evaluation of radiologists' confidence interpreting the mammograms (1 = absolutely certain, 2 = fairly certain, 3 = uncertain), shows a significant correlation between decreasing diagnostic certainty and increasing complexity of the mammographic breast parenchymal pattern. That readers are less confident in their interpretation of P2 and DY breast parenchymal patterns has implications for the operation of breast cancer screening programs.     

江苏省医用诊断X射线工作者肿瘤流行病学调查

目的：医用诊断X射线工作者是小剂量长期照射的特定人群,调查旨在研究辐射诱发恶性肿瘤在这一人群中的表现及特点,方法：收集定群队列1950－1996年间恶性肿瘤发病资料,其相对危险（RR）计算采用Epicure(Hirosoft International Corp.1988-1992)中的AMFTT程序。结果该定群队列来自江苏省医院医用诊断X射线工作者和同所医院其他科室医务工作者共7701人,累计观察了215355人年,期间发生恶性肿瘤312例,经性别、年龄调整,照射线全部肿瘤的相对危险RR＞1;妇女乳腺癌的发生率显著增高（RR＝3．3,95％置信区间为1．39－8．07）;实体癌及白血病RR达1．2和2．6;恶性肿瘤的平均发病年龄由对照组的55．0提前至51．3岁;照射组全死因RR为1．2。结论：医用诊断X射线工作者这一群体显现出辐射致癌效应。但要得出全面的结论仍需继续追踪观察。     

5307名女性乳腺首次筛查影像结果分析

目的 探讨X线、超声和体检3种筛查组合方法对早期乳腺癌检出的意义,分析筛查癌的特点.方法 对5307名女性乳腺进行初次筛查,受检者年龄20～76岁(中位年龄49岁).分析X线加超声和体检、X线加体检、X线检查3种筛查组合的回叫率、活检率和癌检出率,并对筛查癌进行影像分析.各组间比较使用行×列的X2检验或者Fisher's精确检验.结果 X线加超声和体检、X线加体检、X线检查3种筛查组合比较如下:回叫率分别为4.90%(49/1001)、6.90%(166/2407)、4.48%(85/1899);活检率为1.60%(16/1001)、1.04%(25/2407)、0.163%(12/1899);癌检出率为0.50%(5/1001)、0.17%(4/2407)、0(0/1899).X线加超声和体格检查的癌检出率最高,共发现10例乳腺癌,其中9例为筛检癌.3组间的回叫率、活检率和癌检出率比较差异均有统计学意义(X2值分别为12.99、6.264、8.764,P值均<0.05).筛检癌中8例为早期乳腺癌(导管原位癌4例,Ⅰ期浸润性乳腺癌4例).X线检出的7例病灶中仅2例被超声发现,其他5例超声和体检均未检出.表现为簇状分布的多形性钙化2例,交界性钙化呈线样分布2例,不对称致密、不对称致密伴钙化、多簇状钙化伴多发结节各1例.X线漏诊的2例经回顾性阅片都予以正确诊断,均表现为非对称致密影.结论 X线加超声和体格检查3者组合是乳腺癌筛查的最佳组合,X线检查检出的病灶较其他方法更为早期.     

Mammographic parenchymal patterns as risk indicators for incident cancer in a screening program: an extended analysis.

In a screening program of self-referred women, different mammographic parenchymal patterns were related to significantly different rates for developing breast cancer. The risk of cancer detection subsequent to a negative mammographic examination was 7.6 times greater for women in the highest parenchymal risk class compared with the lowest, an increase in risk comparable to that of a personal history of breast cancer and greater than that reported for any other combination of historical risk factors. These differences are qualitatively similar to, but of a lesser magnitude than, those in previous reports which were based on symptomatic women with previous negative mammograms. Data suggest this difference in risk is inherent between parenchymal patterns, rather than indicating difficulty in identifying small cancers in dense breasts. Findings of differential parenchymal risk, coupled with other risk factors, may lead to concentrating mammographic screening on a smaller segment of the population, thus improving the benefit-to-cost ratio.     

The incremental contribution of clinical breast examination to invasive cancer detection in a mammography screening program

OBJECTIVE: The objective of this study was to determine the potential added contribution of clinical breast examination (CBE) to invasive breast cancer detection in a mammography screening program, by categories of age and breast density. SUBJECTS AND METHODS: We prospectively followed 61,688 women aged 40 years or older who had undergone at least one screening examination with mammography and CBE between January 1, 1996, and December 31, 2000, for 1 year after their mammogram for invasive cancer. We computed the incremental sensitivity, specificity, and positive predictive value of CBE over mammography alone for combinations of age and breast density (predominantly fatty or dense). RESULTS: Mammography sensitivity was 78% and combined mammography-CBE sensitivity was 82%, thus CBE detected an additional 4% of invasive cancers. CBE detected a minority of invasive cancers compared with mammography for all age groups and all breast densities. Sensitivity increased from adding CBE to screening mammography for all ages, from 6.8% in women ages 50-59 with dense breasts to 1.8% in women ages 60-69 years with fatty breasts. CBE generally added incrementally more to sensitivity among women with dense breasts. Specificity and positive predictive value declined when CBE was used in conjunction with mammography, and this decrement was more pronounced in women with dense breasts. CONCLUSION: CBE had modest incremental benefit to invasive cancer detection over mammography alone in a screening program, but also led to greater risk of false-positive results. These risks and benefits were greater in women with dense breasts. The balance of risks and benefits must be weighed carefully when evaluating the inclusion of CBE in a screening examination.     

Breast compression and reported pain during mammographic screening

IntroductionWe aimed to investigate the association between breast compression and experienced pain during mammographic screening.MethodsUsing a questionnaire, we collected information on pain experienced during mammography from 1155 women screened in Akershus, February–March 2018, as a part of BreastScreen Norway. The questionnaire provided information on pain using a numeric rating scale (NRS, 0–10) and related factors. Data on compression force (Newton, N), pressure (kilopascal, kPa) and breast characteristics were extracted from the DICOM-header and a breast density software. Log-binomial regression was used to determine the relative risk (RR) of severe versus mild/moderate experienced pain associated with compression parameters, adjusting for breast characteristics and related factors.ResultsMean score of experienced pain was 2.2, whereas 6% of the women reported severe pain (≥7) during the examination. High body mass index (BMI) (≥27.3 kg/m²) was associated with a higher RR of pain scores ≥7 (RR 1.86, 95%CI 1.02–3.36) compared to medium BMI (23.7–27.2 kg/m²). Low compression pressure (4.0–10.2 kPa) was associated with a higher RR of severe pain (RR 2.93, 95%CI 1.39–6.20), compared with medium compression pressure (10.3–13.5 kPa) after adjusting for contact area, age, compressed breast thickness, volumetric breast density and BMI. The risk of severe versus mild/moderate pain (≥7 versus <7) decreased by 2% with increasing compression force (RR 0.98, 95%CI 0.97–1.00).ConclusionWomen reported low levels of pain during mammography. Further knowledge about factors affecting experienced pain is needed to personalize the examination to the individual woman.Implications for practicePain in shoulder(s) and/or neck prior to screening should be considered by the radiographers in a practical screening setting. A compression force of 100–140 N and pressure of 10.3–13.5 kPa are acceptable with respect to reported pain during mammography.     

Breast magnetic resonance imaging

Mammography has long been considered the gold standard for screening breast cancer. Although it reduces the risk of breast cancer mortality by enabling early diagnosis, it does not detect all breast cancers. Numerous breast imaging technologies are emerging as effective adjunctive diagnostic tools when mammography results are negative or inconclusive. Contrast-enhanced magnetic resonance (CE-MR) imaging, in particular, has demonstrated a high sensitivity and has proven to be most effective, especially with patients at high risk for developing breast cancer. This article discusses the clinical applications for breast MR imaging, use of CE-MR for breast cancer detection, and other emerging breast imaging technologies.