37 Bridging the gap between oncology and primary care: a multidisciplinary approach

Arielle Davidson, PharmD candidate

Emily Mackler, PharmD, BCOP

Amy N. Thompson, PharmD, BCACP

Topic Area


Learning Objectives

At the end of this case, students will be able to:

  • Describe the co-management of patients with cancer and certain comorbidities
  • Identify the role of pharmacists in improving care in patients with cancer
  • Discuss instances where high-risk cancer patients need support from a primary care pharmacist
  • Explain the relationship between the impact of cancer on comorbidities and the effect of comorbidities on cancer outcomes


Cancer therapy is increasingly shifting from cytotoxic to molecular targeted treatments, with an expanded number of oral anticancer agents (OAA) being approved and used.1 In addition, the average duration of cancer therapy treatment has doubled in the last decade from four months in the late 1990s to nine months in 2010-2014.1 OAA are taken for more extended periods of time, transforming cancer treatment management to be similar to that of many chronic diseases. Accordingly, cancer treatment regimens introduce drug interactions with other treatments and can cause worsen the severity of comorbid disease states.2

A significant proportion of patients with cancer have one or more comorbidities. Among Medicare patients 65 or older with cancer, 40% have at least one comorbidity and 15% have two or more, with the most common being cardiovascular disease, diabetes mellitus, and mental health disorders.2 OAA treatments such as tyrosine kinase inhibitors, endocrine therapy, and steroids can aggravate a number of different chronic conditions. Hormonal therapies are known to induce metabolic changes that can lead to worsening diabetes control and complications. Anthracyclines and anti-human epidermal growth factor receptor 2 (anti-HER2) therapies are associated with the development of cardiac failure. Lastly, hormonal treatment for breast and prostate cancer can cause a greater likelihood and severity of osteoporosis.2 In addition, cancer outcomes can be affected by comorbidities due to their impact on treatment toxicity, effectiveness, tolerability, and overall survival. As an example of how comorbidities can impact cancer treatment tolerability, patients with severe renal impairment may not be able to endure chemotherapy that is nephrotoxic, so they must instead be considered for other chemotherapy drugs.2 Due to the amount of people with cancer and comorbidities, there is a clear need for collaboration between primary care providers (PCPs) and oncology specialists to ensure proper patient care and positive outcomes.2-5

Pharmacists are best suited to bridge the gaps missing between primary care and oncology due to their versatility and expertise. Studies have shown that one-third of patients with cancer are affected by drug interactions.6 Through performing comprehensive medication reviews (CMRs), pharmacists can resolve these interactions and optimize medication therapy. Additionally, pharmacists can manage adverse effects, which are more likely when patients are taking multiple potentially interacting medications.6-8 Primary care pharmacists can be utilized to assist in coordinating care, identifying, and managing adverse reactions, and improving medication use. While primary care pharmacists can complete these CMRs, they are also able to reach out to oncology pharmacists for any questions or help needed on cancer treatment and care. The management recommendations from the CMR can be discussed with the primary care physician as well as the oncologist. The long-term goal is to improve disease state management, decrease unplanned healthcare utilization, and decrease drug interactions and cancer therapy toxicity. This presents a huge opportunity for pharmacists to enhance patient care and outcomes for patients with cancer and comorbidities.



You are a pharmacist in the primary care setting seeing a patient to conduct a CMR.

CC: “I was contacted and encouraged to follow-up with you to review my medications.”

Patient: PH is a 73-year-old woman (61 in, 77 kg).

HPI: During the visit with the primary care pharmacist, PH reports having high blood pressures with low heart rates. She also communicates concerns about her diet and exercise regimen, and her stools having been darker recently, but believes her oncologist said this was a potential side effect of her therapy. Lastly, she describes back pain and knee arthritis.


  • History of breast cancer (2004)
  • Angiosarcoma of the breast (2016)
  • Uncontrolled HTN
  • GERD
  • Major depressive disorder
  • Myalgia
  • Recurrent UTI
  • Urgency incontinence
  • T2DM


  • Mother: breast cancer, heart disease, melanoma
  • Father: lung cancer, stomach cancer, brain cancer
  • Sister: breast cancer
  • Brother: heart disease, melanoma
  • Maternal aunt: breast cancer
  • Paternal grandmother: brain cancer
  • Paternal grandfather: clotting disorder, lung cancer


  • Former smoker (quit 19 years ago; two packs per day x 30 years)
  • Alcohol: two drinks/week

Medications: PH reports excellent adherence to prescribed medications with missed doses occurring rarely ever. Further pertinent findings discovered during medication reconciliation include:

  • Fulvestrant 500 mg IM every 28 days
  • Palbociclib 125 mg daily for 21 days followed by 7 days off, for 28-day cycles
  • Enalapril 2.5 mg daily
    • Patient reports dry cough nightly since starting 2-3 months ago
  • Amlodipine 10 mg daily
  • Meloxicam 15 mg BID
  • Ranitidine 150 mg BID
    • Patient reports “really bad” GERD symptoms and tarry stools
    • Provides little relief
  • Metformin 1 g BID
  • Glipizide XL 5 mg daily
  • Duloxetine 60 mg daily in the morning
    • Patient reports limited relief of neuropathy, with her toes completely numb
  • Gabapentin 300 mg in the morning and 600mg at bedtime
    • Patient reports only taking 300mg in the morning and 300mg in the evening
    • She reports getting groggy in morning if she takes 600mg at night
  • Ondansetron orally disintegrating tab 8mg every eight hours PRN nausea
  • Imodium 2 mg four times daily PRN diarrhea


  • Codeine: N/V, dizziness
  • Sulfa antibiotics: severe rash
  • Sulfamethoxazole-trimethoprim: hives, edema
  • Tramadol: nausea
  • Ciprofloxacin: itching


  • BP 155/85 mmHg
  • HR 55 bpm
  • RR 18/min

Labs: From three weeks ago:

Parameter Value Parameter Value
Na 139 mEq/L Glu 75 mg/dL
K 4.6 mEq/ Ca 8.9 mg/dL
Cl 106 mEq/L Alk phos 140 IU/L
CO2 27 mEq/L AST 34 IU/L
BUN 29 mg/dL ALT 39 IU/L
SCr 0.74 mg/dL HgbA1c 8.2%

SDH: Patient is retired, widowed, and dealing with financial hardship. She uses Medicare as the primary means of paying for medications with little to no difficulty affording them. She was living in Alabama until the death of her husband last year. She has since moved back to Michigan where she is closer to her children and grandchildren. She reports difficulty getting to and from her visits and that she does not have much social interaction as her family is often busy.

Additional context: PH states her diet is not good. She enjoys cooking and baking but feels like she is hungry all the time. Despite this, she tries not to eat after 6pm each night. A typical day of eating for her includes a breakfast with eggs, bagel/English muffin, bacon/sausage and “weak coffee,” lunch with a half sandwich with avocado and tomato, and dinner with either spaghetti, meat/potatoes, hamburgers, broccoli/zucchini. She may incorporate snacks with fruit or yogurt and drinks a lot of water (no pop or iced tea). Overall, PH says she is “not a big veggie person” and states she “grabs junk stuff.” She is very motivated to improve her diet and would like to see a dietician. She states that she is not exercising currently, but she has a friend that is western dancing and is interested to start doing this again soon. However, she has recently gained 25lbs, which she is not pleased about. However, she is motivated to make changes for the better.

Case Questions

1. What patient factors must you take into consideration when optimizing PH’s medication regimen?

2. What SDH/SDOH might be relevant to PH’s situation?

3. What might the primary care pharmacist need to refer to the oncology pharmacist for?

4. What are impacts of cancer therapies on comorbid conditions, considering this patient’s current medical history?

5. What specific gaps in care can you identify with PH and how can you as the pharmacist assist her?

6. Based on the medication reconciliation performed in the clinic today, what changes to her therapy would you recommend to the PCP?

7. What lifestyle recommendations would you recommend for PH?

Author Commentary

Coordination of care can be complicated for patients with cancer. Oftentimes, primary care will take a step back when there is a cancer diagnosis. In some cases, the oncologist acts as the primary provider during cancer treatment, which can result in suboptimal care of non-cancer comorbidities.9 Forty percent of oncologists report having ongoing communication with PCPs, and both oncologists and PCPs both acknowledge the PCP’s lack of experience in cancer care as another barrier.10 Accordingly, there is uncertainty regarding which aspects each team can and will manage.10 The suboptimal care, lack of communication, and knowledge barrier leaves a gap in care for a very large population of patients. While it might not be feasible for the oncologist to keep in constant communication with the PCP, it is an opportunity for a non-physician team member such as a pharmacist to take on this role.11 With pharmacists working to optimize medications and serve as a source of communication, they are directly enhancing patient care. Involvement of a pharmacist has a positive impact on clinical outcomes and decreases unplanned healthcare utilization.12

Patient Approaches and Opportunities

Pharmacists have multiple opportunities to positively impact patients with cancer and other comorbid conditions. Pharmacists can serve an essential role with medication reconciliation, review, and optimization alongside the primary care physician or oncologist. Pharmacists are also utilized to educate patients on expected side effects from cancer treatment, as well as methods that can be used to mitigate such side effects. For example, pharmacists can inform patients of possible chemotherapy induced nausea and vomiting and can speak with the PCP about prescribing ondansetron if needed. In addition, pharmacists can engage patients in conversations regarding their medications, identifying any adverse reactions or interactions that the patient may have either knowingly or unknowingly encountered. By looking specifically for interactions between cancer and non-cancer therapies, pharmacists can suggest ways to decrease use of unnecessary medications. They can also counsel on the importance of adherence to maintaining overall health, combat medication-related problems, make changes, and communicate with the primary care physician and oncologist throughout the whole process. In addition, pharmacists are in an ideal position to help shift to a path that proactively identifies patients at highest risk for toxicities or complications from their cancer treatment to help impact the care for this patient population.13 The accessibility and resourcefulness of pharmacists makes them very beneficial to patients and the health system.

Important Resources

Related chapters of interest:

External resources:

  • Michigan Oncology Quality Consortium. https://moqc.org/
  • Mohamed M, Ramsdale E, Loh K, Arastu A, Xu H, Spencer O, et al. Associations of polypharmacy and inappropriate medications with adverse outcomes in older adults with cancer: a systematic review and meta-analysis. Oncologist 2020;25:e94-e108.
  • DeZeeuw E, Coleman A, Nahata M. Impact of telephonic comprehensive medication reviews on patient outcomes. Am J Manag Care 2018;24(2):e54-8.
  • Viswanathan M, Kahwati LC, Golin CE, Blalock Sj, Coker-Schwinner E, Posey R, et al. Medication therapy management interventions in the outpatient settings. JAMA Intern Med 2015;175(1):76-87.


  1. Savage P, Mahmoud S. Development and economic trend in cancer therapeutic drugs: A 5 year update 2010-2014. Br J Cancer 2015;112:1037-41.
  2. Sarfati D, Koczwara B, Jackson C. The impact of comorbidity on cancer and its treatment. CA Cancer J Clin 2016;66(4):337-50.
  3. Cuthbert C, Hemmelgarn B, Xu Y, Cheung W. The effect of comorbidities on outcomes in colorectal cancer survivors: a population-based cohort study. J Cancer Surviv 2018;12(6):733-43.
  4. Yancik R, Wesley M, Ries L, et al. Effect of age and comorbidity in postmenopausal breast cancer patients aged 55 years and older. JAMA 2001;285(7):885-92.
  5. Riechelmann R, Tannock I, Wang L, Saad E, Taback N, Krzyzanowska M. Potential drug interactions and duplicate prescriptions among cancer patients. J Natl Cancer Inst 2007;99(8):592-600.
  6. Riechelmann R, Zimmermann C, Chin S, Wang L, O’carroll A, Zarinehbaf S, et al. Potential drug interactions in cancer patients receiving supportive care exclusively. J Pain Symptom Manage 2008;35(5):535-43.
  7. Miranda V, Fede A, Nobuo M, Ayres V, Giglio A, Miranda M, et al. Adverse drug reactions and drug interactions as causes of hospital admission in oncology. J Pain Symptom Manage 2011;42(3):342-53.
  8. Dossett L, Hudson J, Morris A, Lee M, Roetzheim R, Fetters M, et al. The primary care provider (PCP)-cancer specialist relationship: A systematic review and mixed-methods meta-synthesis. CA Cancer J Clin 2016;67(2):156-69.
  9. Lee S, Clark M, Cox J, Needles B, Seigel C, Balasubramanian B. Achieving coordinated care for patients with complex cases of cancer: A multiteam system approach. J Oncol Practice 2016;12(11):1029-38.
  10. Stegmann M, Homburg T, Meijer J, Nuver J, Havenga K, Hiltermann T, et al. Correspondence between primary and secondary care about patients with cancer: a delphi consensus study. Support Care Cancer 2019;27:4199-4205.
  11. Rotenstein L, Zhang Y, Jacobson J. Chronic comorbidity among patients with cancer: an impetus for oncology and primary care collaboration. JAMA Oncol 2019;5(8):1099- 1100.
  12. Viktil K, Blix, H. The impact of clinical pharmacists on drug-related problems and clinical outcomes. Basic Clin Pharmacol Tox 2008;102(3):275-80.
  13. Hurria A, Mohile S, Gajra A, Klepin H, Muss H, Chapman A, et al. Validation of a prediction tool for chemotherapy toxicity in older adults with cancer. J Clin Oncol 2016;34(20):2366-7.

Glossary and Abbreviations


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Public Health in Pharmacy Practice: A Casebook Copyright © by Jordan R Covvey, Vibhuti Arya, Natalie DiPietro Mager, Neyda Gilman, MaRanda Herring, Stephanie Lukas, Leslie Ochs, and Lindsay Waddington is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

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