Well water contamination in heavily agricultural regions has previously been linked with increased cancer incidence and mortality. The lower Eastern shore of Maryland is a rural, agricultural region with some of the highest rates of cancer in Maryland and the United States. Our study sought to characterize residential private well water use among cancer patients on the lower Eastern shore of Maryland, and to compare private well water utilization between cancer patients and the general regional population. Retrospective chart review was conducted to identify patients diagnosed with colon, lung, melanoma or breast cancer at a regional hospital from 1 January 2017 through 31 December 2018. Residential water source was determined using residential address and municipal water records. Fisher’s exact test was used to compare residential private well water utilization between our study population and the baseline regional population. The majority of cancer patients (57%) lived in homes supplied by private well water (428/746). Cancer patients were more likely to live in homes supplied by private well water compared to individuals in the general regional population (57% vs. 32%, p < 0.001). In conclusion, cancer patients on the lower Eastern shore of Maryland were more likely to live in homes supplied by residential private well water than the regional population. Additional studies are needed to evaluate well water use and cancer risk in this vulnerable region.

In non‐small‐cell lung cancer (NSCLC), activating human epidermal growth factor receptor 2 (HER2) mutations are found in a small subset of patients and are associated with a higher incidence of brain metastases (BMETSs), conferring poor survival outcomes. Trastuzumab deruxtecan (T‐DXd) was recently approved as a second‐line agent for use in patients with previously treated, unresectable, or metastatic HER2‐mutated NSCLC. We present a case of HER2‐mutated NSCLC with BMETS, treated with T‐DXd to defer whole‐brain radiotherapy (WBRT) because of the concern of long‐term neurotoxicity. He initially also received bevacizumab to address the cerebral edema, which allowed stopping corticosteroids. After the first two doses, the patient had remarkable clinical and imaging (brain and systemic) responses without progression after more than 1 year of treatment. T‐DXd may be an effective and durable therapy for patients with HER2‐mutated NSCLC with brain metastases in situations where intracranial disease would otherwise warrant WBRT. Clinical trials are needed to understand the efficacy and durability of T‐DXd in NSCLC with BMETS and the optimal sequence of available therapies.

This chapter reviews the initial assessment and management of metastatic breast cancer (MBC). It reviews hormonal therapy (HT), combination hormonal and targeted therapy, single agent chemotherapy, and combination chemotherapy. Selective estrogen receptor modulators (SERMs) such as tamoxifen have been used for many years for the treatment of MBC, although with limited data for the premenopausal population. There are no prospective data that demonstrate conclusively that combination chemotherapy improves survival when compared to single agent cytotoxic chemotherapy for treatment of MBC. Anthracyclines are active agents in the treatment of MBC. A patient with MBC who does not want intravenous (IV) chemotherapy may choose to start with the oral capecitabine. Coupled with the fact that patients with bone only metastases tend to have longer survival and bone metastases may be associated with significant morbidity, bone metastases present a diverse challenge in the treatment of MBC.

Krukenberg tumors are rare cancers involving metastatic disease in the ovaries but classically originate from gastrointestinal malignancies, and often present diagnostic challenges due to their nonspecific symptoms and advanced stage at detection. Traditional imaging techniques like ultrasound, CT, and MRI are common methods of cancer monitoring but are limited in detecting micrometastatic disease and early‐stage metastases. Circulating tumor DNA (ctDNA) testing, a noninvasive liquid biopsy method, offers a promising alternative to traditional screening methods, enabling earlier detection and precise molecular profiling of metastatic tumors. We present a case study involving a female patient who initially presented with stage IV colon cancer with oligometastatic disease to a single mesenteric lymph node. Despite neoadjuvant chemotherapy and resection of known disease, postresection ctDNA returned positive. Imaging after metastectomy failed to reveal any sites of ongoing disease, although did show a small, 2.4‐cm hypodensity in the right ovary interpreted by radiology as likely an ovarian follicle. Given her ctDNA positivity, she was started on capecitabine. ctDNA levels improved, but her serum carcinoembryonic antigen (CEA) tumor marker continued to rise, and imaging subsequently revealed increased bilateral ovarian masses. She underwent bilateral salpingo‐oophorectomy and total abdominal hysterectomy, with pathology confirming metastatic colon adenocarcinoma, and subsequent normalization of her CEA and ctDNA levels. Our findings underscore ctDNA’s potential to complement imaging, particularly for high‐risk patients, for disease monitoring and to refine therapeutic management when treating Krukenberg tumors.