A biosimilar is a biochemical product like another already approved biologic agent, known as the reference agent. To be endorsed by the Food and Drug Administration (FDA), biosimilars must demonstrate that they are as safe and effective as their reference item, with no clinical distinction. Humanized monoclonal antibodies (mAb) are revolutionizing the treatment of gastrointestinal and gynecologic malignancies. Bevacizumab, trastuzumab, cetuximab, rituximab, and pegfilgrastim are the most widely used mAb products with oncologic indications. Due to the complexities of the regulatory system, it may take time for anti-cancer biosimilars to play a significant game-changing role. Over the last decade, the use of generics has saved billions of dollars every year, and it is expected that biosimilars will soon prove to be a cost-effective alternative and can play an important role in driving down healthcare costs globally. In this review, we provide a critical appraisal of biosimilars with an emphasis on bevacizumabawwb (Avastin) and its clinico-pharmacologic characteristics, safety, efficacy, interchangeability, regulatory and oncologic perspectives, and overall clinical perception.

Breast cancer is the most common cancer in women. The common sites of metastasis include the lungs, liver, and, infrequently, the gastrointestinal (GI) tract. A 72-year-old Caucasian female presented to the hospital with nausea and vomiting, diarrhea, intermittent abdominal pain, and unintentional weight loss. She had had a past medical history of bilateral lobular breast carcinoma and severe iron-deficiency anemia treated with iron transfusions. On arrival, the examination was significant for hypotension and pallor. Laboratory investigations revealed abnormal liver enzymes and raised tumor markers Ca-125 and carcinoembryonic antigen. Imaging studies established a diagnosis of distal small bowel obstruction. The surgical intervention showed the presence of a small bowel tumor, the biopsy findings of which were consistent with metastatic breast cancer, with ER and PR positive but HER-2 negative. She was managed with a selective estrogen receptor degrader and CDK4/6 inhibitor and has been in remission since. Metastasis to the small bowel from the breast is a very rare occurrence. Clinicians should thus maintain a modest amount of suspicion when encountering an uncommon GI presentation of primary breast malignancy. We describe the case of metastatic breast cancer with an atypical GI presentation.

Endometrial stromal cell sarcomas (ESS) are a unique subtype of uterine malignancy. Recurrent low grade endometrial stromal sarcomas (LESS) is identified in half of the patients. Here, we discuss a case of a 76-year-old Asian female with a past medical history of adenomyosis and hypertension who presented to the outpatient clinic with a chief complaint of painless hematuria for one day. Computed tomography scan of abdomen and pelvis with contrast showed a new right-sided mixed cystic and solid pelvic mass measuring up to 6 cm, obstructing and invading the distal right ureter, which was concerning for malignancy. Positron emission tomography (PET scan) demonstrated a right pelvic mass with increased radiotracer activity consistent with malignancy. She underwent laparotomy with excision of the right-sided pelvic mass with an abdominal washout and at the same time, also underwent cystoscopy with right ureteral stent placement. Tissue pathology was consistent with spindle cell neoplasm with staining and histologic features consistent with a recurrent stromal cell sarcoma. Uterine sarcomas tend to have an aggressive nature but there are key features about ESS that distinguish it from other uterine sarcomas. ESS has a more indolent clinical course and can reoccur years after initial diagnosis. They usually relapse locally, although relapses in extrauterine sites have also been reported. Treatment of ESS depends on the grade and stage at the time of diagnosis. The main line of treatment for ESS consists of a total abdominal hysterectomy (TAH) and salpingo-oophorectomy (BSO). The significance of this case demonstrates that, although remission can be obtained after the initial diagnosis, recurrence can happen. Even when patients seem to be disease-free, clinicians should follow them closely; early diagnosis is important as treatment for this type of entity has a high survival rate.

Drug-induced immune hemolytic anemia (DIIHA) is a rare cause of anemia. It is often difficult to distinguish from other causes of hemolytic anemia, thereby delaying diagnosis and treatment. Antibiotics, including penicillins and cephalosporins, are the drugs most often implicated in the development of DIIHA. Discontinuation of the offending agent is often sufficient for treatment. Here, we review the case of a 25-year-old Caucasian female who presented with jaundice and generalized weakness in the setting of outpatient treatment with amoxicillin-clavulanate due to sinus infection. Laboratory testing revealed transaminitis and hemolytic anemia. Direct antiglobulin test (DAT) revealed negative IgG and positive anti-C3. Cold agglutinin titer and Donath-Landsteiner test were negative. The patient was diagnosed with DIIHA most likely due to amoxicillin. She improved with drug cessation and a short course of glucocorticoids. Mechanism of DIIHA, workup, and management are subsequently reviewed.