Which of the following statement(s) is/are true concerning non-invasive breast carcinoma?

a. Ductal carcinoma in situ (DCIS) is associated with a significant risk of development of invasive ductal carcinoma in the same quadrant of the same breast as the initial lesion

d. When LCIS is found, there is an up to 50% chance of lobular carcinoma in situ of the contralateral breast

Non-invasive (in situ) cancer is defined as a neoplastic entity within the epithelium of origin and without invasion to the basement membrane. Ductal carcinoma in situ (DCIS) arises from the ductular elements. The age distribution of DCIS does not differ significantly from that of invasive ductal carcinoma. Not every woman who undergoes complete excision of a focus DCIS develops invasive ductal cancer. Various studies suggest half or more patients develop invasive breast cancer after excisional biopsy alone. When a subsequent invasive cancer does occur, it is almost always of the invasive ductal type and located in the same quadrant of the breast as the initial DCIS. The latent period before the development of invasive cancer usually exceeds five years. Total mastectomy is usually associated with a nearly 100% cure rate for this condition. Although total mastectomy remains the gold-standard for treatment of DCIS, there is increasing experience with breast-conserving therapy. Breast conservation may be offered to DCIS patients in whom the entire tumor can be surgically removed with negative histologic margins and in whom the remaining breast tissue can be reliably assessed clinically and radiographically. It would appear that the disease-free survival following lumpectomy and radiation therapy is worse than that achievable with simple mastectomy. Therefore, breast conservation for DCIS commits patients to more careful long-term follow-up and will likely subject them to additional subsequent treatment to deal with the recurrences. Lobular carcinoma in situ (LCIS) accounts for one-third of the noninvasive breast cancers. LCIS patients are significantly younger than patients with invasive breast cancer. Three-fourths of affected women are pre-menopausal. LCIS is an infrequent finding in women over 75. When the opposite breast is sampled at the time of diagnosis, contralateral LCIS is found in 30–50% of cases. The prognosis of LCIS is solely related to the subsequent development of invasive carcinoma. About one-third of patients with biopsy-demonstrated LCIS develop invasive cancer; half occur in the index breast and half in the contralateral breast. The subsequent breast cancers can be either lobular or ductal in histology.