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Dr. Shaheen specializes in the gastrointestinal malignancies and she has expertise in treating neuroendocrine tumors (NETs). Following her fellowship in Hematology and Oncology, Dr Shaheen completed an advanced fellowship in Neuroendocrine tumors from Stanford University. The NET advanced fellowship is first of its kind in United State started under the leadership of Dr Pamela Kunz who is the founding Director of the Stanford Neuroendocrine Tumor Program established in 2015. After completing her advanced fellowship, Dr Shaheen joined Stanford Oncology division as Clinical Assistant Professor. Dr Shaheen is involved in further developing the neuroendocrine oncology program at Stanford which serves as a centre of excellence in the treatment of neuroendocrine tumors. Dr Shaheen is actively involved in clinical research and clinical trials. Dr Shaheen is also involved in taking care of patients admitted to the oncology service as well as resident and fellow teaching.

Clinical Focus

  • Medical Oncology

Academic Appointments

Professional Education

  • Board Certification: American Board of Internal Medicine, Internal Medicine (2010)
  • Fellowship: Stanford Hospital and Clinics Neuro-Oncology Fellowship CA
  • Board Certification: American Board of Internal Medicine, Medical Oncology (2018)
  • Fellowship: Loma Linda University Hematology and Medical Oncology Fellowship (2018) CA
  • Residency: St Joseph Hospital Internal Medicine Residency (2010) IL
  • Medical Education: MGM Medical College (2004) India
  • Fellowship, Stanford University, Neuroendocrine Tumor Fellowship (2019)
  • Fellowship, Loma Linda University, Hematology and Oncology Fellowship (2018)
  • Residency, Saint Joseph University of Illinois at Chicago, Internal Medicine (2010)
  • Internship, Government Medical College, Kashmir, Internship (2003)
  • Medical Education, MGM Medical College, India, Bachelor of Medicine and Surgery (2002)
  • Board Certification, American Board of Internal Medicine, Medical Oncology (2018)
  • Board Certification, American Board of Internal Medicine, Internal Medicine (2010)

Research & Scholarship

Clinical Trials

  • Testing Cabozantinib in Patients With Advanced Pancreatic Neuroendocrine and Carcinoid Tumors Recruiting

    This randomized phase III trial studies cabozantinib to see how well it works compared with placebo in treating patients with neuroendocrine or carcinoid tumors that have spread to other places in the body (advanced). Cabozantinib is a chemotherapy drug known as a tyrosine kinase inhibitor, and it targets specific tyrosine kinase receptors, that when blocked, may slow tumor growth.

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  • Capecitabine, Temozolomide, and Bevacizumab for Metastatic or Unresectable Pancreatic Neuroendocrine Tumors Not Recruiting

    The purpose of this research is to evaluate the effectiveness and safety of a combination of capecitabine, temozolomide and bevacizumab in the treatment of advanced pancreatic neuroendocrine tumors.

    Stanford is currently not accepting patients for this trial. For more information, please contact Ben Priestley, 650-723-2990.

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All Publications

  • Prevalence of Bone Metastases in Neuroendocrine Neoplasms by 68Ga DOTATATE PET Scan Shaheen, S., Gardner, R., Sundaram, V., Hornbacker, K., Moradi, F., Wu, J., Kunz, P. LIPPINCOTT WILLIAMS & WILKINS. 2020: 486
  • Patient Selection and Toxicities of PRRT for Metastatic Neuroendocrine Tumors and Research Opportunities. Current treatment options in oncology Shaheen, S. n., Moradi, F. n., Gamino, G. n., Kunz, P. L. 2020; 21 (4): 25


    Neuroendocrine tumors (NETs) are a heterogenous group of neoplasms characterized by varied biological hallmarks and behavior, ranging from indolent to aggressive. For many decades, somatostatin analogues and few targeted therapies were available for NETs and these therapies had minimal response rates. However, there have been a number of recent treatment advances. Peptide receptor radionuclide therapy (PRRT) is a novel approach to treatment of NETs and has changed the landscape of treatment for NETs. It is a form of targeted therapy in which a radiolabeled somatostatin analogue delivers radiation specifically to tumor cells expressing the somatostatin receptor.

    View details for DOI 10.1007/s11864-020-0711-9

    View details for PubMedID 32172368

  • Targeted and novel therapy in advanced gastric cancer EXPERIMENTAL HEMATOLOGY & ONCOLOGY Selim, J. H., Shaheen, S., Sheu, W., Hsueh, C. 2019; 8 (1): 25


    The systemic treatment options for advanced gastric cancer (GC) have evolved rapidly in recent years. We have reviewed the recent data of clinical trial incorporating targeted agents, including inhibitors of angiogenesis, human epidermal growth factor receptor 2 (HER2), mesenchymal-epithelial transition, epidermal growth factor receptor, mammalian target of rapamycin, claudin-18.2, programmed death-1 and DNA. Addition of trastuzumab to platinum-based chemotherapy has become standard of care as front-line therapy in advanced GC overexpressing HER2. In the second-line setting, ramucirumab with paclitaxel significantly improves overall survival compared to paclitaxel alone. For patients with refractory disease, apatinib, nivolumab, ramucirumab and TAS-102 have demonstrated single-agent activity with improved overall survival compared to placebo alone. Pembrolizumab has demonstrated more than 50% response rate in microsatellite instability-high tumors, 15% response rate in tumors expressing programmed death ligand 1, and non-inferior outcome in first-line treatment compared to chemotherapy. This review summarizes the current state and progress of research on targeted therapy for advanced GC.

    View details for DOI 10.1186/s40164-019-0149-6

    View details for Web of Science ID 000489720300002

    View details for PubMedID 31632839

    View details for PubMedCentralID PMC6788003

  • Concomitant KRAS and BRAF mutations in colorectal cancer JOURNAL OF GASTROINTESTINAL ONCOLOGY Midthun, L., Shaheen, S., Deisch, J., Senthil, M., Tsai, J., Hsueh, C. 2019; 10 (3): 577?81
  • Conservative management of nivolumab-induced pericardial effusion: a case report and review of literature. Experimental hematology & oncology Shaheen, S. n., Mirshahidi, H. n., Nagaraj, G. n., Hsueh, C. T. 2018; 7: 11


    Nivolumab is an immune checkpoint inhibitor targeting programmed death-1 protein and has been approved for the treatment of multiple advanced malignancies. Adverse effects of immune checkpoint inhibitors are distinct from conventional cytotoxic chemotherapy and can be life-threatening if left unrecognized. Here, we present a case of nivolumab-induced pericardial effusion successfully managed with high-dose corticosteroids.A 70-year-old Caucasian female with a history of 50-pack-year cigarette smoking was diagnosed of recurrent adenocarcinoma of lung after initial surgery. She progressed through multiple lines of chemotherapy and was eventually started on nivolumab. She developed a large pericardial effusion, grade 3 by Common Terminology Criteria for Adverse Events v4.0, about 4 days after receiving first nivolumab treatment. She was treated with oral prednisone at 1 mg/kg daily with gradual resolution of pericardial effusion over 5 weeks while she still received nivolumab every 2 weeks. Prednisone treatment was eventually tapered off about 10 weeks from initial nivolumab treatment. However 1 week after stopping prednisone, she again presented with shortness of breath and bilateral ankle edema, imaging confirmed recurrent pericardial effusion measuring 2.8 cm. Nivolumab was stopped and patient was again started back on prednisone 1 mg/kg daily which resulted in complete resolution of pericardial effusion in 3 weeks. Nivolumab was resumed 1 week afterwards while patient was on tapering dose of prednisone. There was no recurrent pericardial effusion when she continued low-dose prednisone during the remaining course of nivolumab treatment.With increasing use of immune checkpoint inhibitors, clinicians need to be aware of the unusual immune-related adverse events in order to provide timely management and effective patient care. To our knowledge, this is the first reported case of immune-related pericardial effusion from nivolumab successfully managed with high-dose corticosteroids. Furthermore, recurrent pericardial effusion was prevented by using low-dose corticosteroids as maintenance in order for patient to continue nivolumab treatment.

    View details for DOI 10.1186/s40164-018-0104-y

    View details for PubMedID 29761026

    View details for PubMedCentralID PMC5941729

  • Characterization of disease progression in ovarian cancer by utilizing 'chemograms' of ovarian cancer stem cells. Journal of chemotherapy (Florence, Italy) Guddati, A. K., Shaheen, S. n. 2013; 25 (3): 184?91


    Ovarian cancer is one of the leading causes of death in women with cancer. First-line chemotherapy with platinum compounds and taxane compounds has been effective, but most patients develop a relapse of the disease due to drug resistance. There is growing evidence that this resistance may be due to the presence of ovarian cancer stem cells.Cells with properties of cancer stem cells have been isolated from the ascitic fluid of ovarian cancer patients. This subset of cells is highly tumourigenic compared to the rest of the cells in the ascitic fluid. They are known to exude harmful chemicals from their cytoplasm and have been found to be resistant to chemotherapeutic agents. This property has been utilized to purify them by fluorescence assisted cytometry to yield a subset of cells which are called 'side population'. These cells exhibit the properties of cancer stem cells and their role in disease progression is being currently investigated. The course of the disease can be potentially characterized at the cellular level by closely studying this cell population. They can also be cultured in different combinations of chemotherapeutic agents at varying concentrations to obtain 'chemograms' which are sensitivity charts. Chemotherapeutic agents which produce the most effective kill curves can then be rationally used as a second-line chemotherapy if the disease relapses. These sensitivity charts can provide insight into emerging patterns of chemoresistance and also help discover surface markers that accurately identify ovarian cancer stem cells.The high rate of disease relapse in patients with ovarian cancer requires a new and different approach utilizing the sensitivity of cancer stem cells. Isolating and characterizing the resistance patterns of ovarian cancer stem cells may provide a rational approach towards an effective and individualized chemotherapeutic regimen.

    View details for DOI 10.1179/1973947812Y.0000000058

    View details for PubMedID 23783145

  • Secondary mucosa-associated lymphoid tissue (MALT) lymphoma of the colon. Medical oncology (Northwood, London, England) Shaheen, S. n., Guddati, A. K. 2013; 30 (2): 502


    Mucosa-associated lymphoid tissue (MALT)-type lymphomas most commonly occur in the stomach and have been associated with Helicobacter pylori infection. However, MALT-type lymphoma of the colon is a rare entity. It commonly manifests with symptoms of weight loss, low-grade fever, constipation, melena, and hematochezia. Unlike gastric lymphoma, it is difficult to detect MALT-type lymphoma of the colon by imaging. Colonoscopy may reveal lesions whose biopsy most commonly shows abundant B lymphocytes. There is no universal immunohistochemistry profile for MALT-type lymphoma but CD 20 staining is commonly seen. Trisomies and translocations have been described and their presence has been correlated with treatment response. Due to the rarity of colonic MALT-type lymphoma, no standard guidelines are available for its management. It often occurs individually and rarely occurs simultaneously with concurrent colon adenocarcinoma. This case report describes the presentation and clinical course of a secondary MALT-type lymphoma in a patient who underwent colectomy for a prior colon adenocarcinoma.

    View details for DOI 10.1007/s12032-013-0502-2

    View details for PubMedID 23423787

  • Gastrointestinal stromal tumor: a rare abdominal tumor. Case reports in oncology Shaheen, S. n., Guddati, A. K. 2013; 6 (1): 148?53


    Gastrointestinal stromal tumors (GISTs) are rare abdominal tumors which arise from the interstitial cells of Cajal in the gastrointestinal tract. Gastric GISTs are the most commonly seen GIST tumors and may grow to a very large size. They are often associated with abdominal pain, anorexia and weight loss. Most of them can be detected by CT. These tumors have been found to harbor mutations in CD117 which causes constitutional activation of the tyrosine kinase signaling pathway and is considered to be pathognomic. Tyrosine kinase inhibitors such as imatinib have revolutionized the treatment of these tumors, which are otherwise resistant to conventional chemotherapy and radiotherapy. Although surgical resection is the mainstay of treatment, tyrosine kinase inhibitors have been useful in prolonging the recurrence-free survival of these patients. Resistance to imatinib has been reported in GISTs with specific mutations. We present a case of gastric GIST which grew to a very large size and was associated with abdominal pain and weight loss. It was successfully resected and the patient was commenced on imatinib therapy.

    View details for DOI 10.1159/000350061

    View details for PubMedID 23569450

    View details for PubMedCentralID PMC3618098

  • Uterine leiomyosarcoma manifesting as a tricuspid valve mass. Case reports in oncology Marak, C. P., Ponea, A. M., Alappan, N. n., Shaheen, S. n., Guddati, A. K. 2013; 6 (1): 119?26


    Uterine leiomyosarcoma is a rare malignancy and carries a poorer prognosis when compared to endometrial carcinoma. It has been observed to metastasize to all the major organs. It presents with symptoms of abdominal distension, vaginal bleeding and may pass unnoticed until an advanced stage in patients with leiomyomas. Surgery is a viable option in patients with disease limited to the uterus, but metastasis to the heart may require surgery to prevent acute and catastrophic complications. The case described here involves metastasis to the tricuspid valve, which caused severe tricuspid regurgitation in the setting of acute pulmonary embolism. Surgical resection restored cardiac function and stabilized the patient. This case illustrates a rare site of metastasis of leiomyosarcoma which required immediate intervention and resulted in a favorable outcome.

    View details for DOI 10.1159/000346935

    View details for PubMedID 23569446

    View details for PubMedCentralID PMC3618104

  • Extracavitary manifestation of primary effusion lymphoma as a right atrial mass. Case reports in oncology Marak, C. P., Ponea, A. M., Shim, C. n., Shaheen, S. n., Guddati, A. K. 2013; 6 (1): 114?18


    Primary effusion lymphoma (PEL) is a subset of large B cell lymphomas and has been mostly associated with human immunodeficiency virus infection. Rare cases have been reported in organ transplant recipients and chronic hepatitis C patients. It typically presents as an effusion in the pleural and pericardial spaces but rarely disseminates. However, involvement of the gastrointestinal tract, lymph nodes and bone marrow has been reported. Diagnosis is based on characteristic clinical, histopathological and immunohistochemical features. We present a case with a right atrial mass which tested positive for human herpes virus 8 (HHV-8), CD20, CD30 and lambda light chains and negative for CD138, kappa light chain, PAX5, Epstein-Barr virus, latent membrane protein 1, CD2, CD3, CD8 and CD56. Bilateral pleural effusions and pericardial effusions were noted which tested positive for HHV-8, CD30 and CD45. The patient responded well to the R-EPOCH regimen with complete resolution of the effusions and a significant decrease in the size of the right atrial mass. This case report illustrates the atypical manifestation of PEL as a right atrial mass.

    View details for DOI 10.1159/000346838

    View details for PubMedID 23569445

    View details for PubMedCentralID PMC3618032

  • Cutaneous metastasis of uterine adenocarcinoma: a case report and review of the literature. Cutis Selim, A. A., Shaheen, S. n., Lockshin, N. n., Khachemoune, A. n. 2009; 84 (1): 33?38


    Cutaneous metastases from cancer are relatively uncommon in clinical practice but when present may herald the diagnosis of internal malignancy. The most common sources of primary cancer are the breasts, lungs, large bowel, oral cavity, kidneys, stomach, ovaries, and malignant melanoma. Despite the high incidence of uterine adenocarcinoma, cutaneous metastases are uncommon. The most common presentation of cutaneous metastases is rapidly developing nodules or tumors. The diagnosis of cutaneous metastatic carcinoma hinges on histopathologic evaluation of the involved skin. We discuss and review the diagnosis and management of cutaneous metastasis of uterine adenocarcinoma.

    View details for PubMedID 19743722

  • Melanotic neuroectodermal tumor of infancy: review of literature and case report. Journal of pediatric surgery Selim, H. n., Shaheen, S. n., Barakat, K. n., Selim, A. A. 2008; 43 (6): E25?9


    Melanotic neuroectodermal tumor of infancy (MNTI) is an uncommon, fast-growing, pigmented neoplasm of neural crest origin. It primarily affects the maxilla of the infants during the first year of life. Approximately, a few hundred of these tumors have been reported in medical literature. We present a case of a newborn with MNTI involving the anterior maxillary region. The treatment included surgical excision of the lesion with safe margins, using an intraoral approach and removal of associated developing tooth buds. We made no attempt at immediate bone grafting. The patient had no recurrence at 1 year postoperatively. The diagnostic features and management alternatives of MNTI are discussed.

    View details for DOI 10.1016/j.jpedsurg.2008.02.068

    View details for PubMedID 18558161

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