What is the best next step for a 65-year-old breast cancer patient with metastatic liver disease, presenting with low back pain, positive straight leg test, and mild disc herniation at L4-L5, currently taking anastrazole (aromatase inhibitor), Novus (likely a calcium or vitamin supplement, possibly containing calcium (Ca) and vitamin D), lisinopril (angiotensin-converting enzyme inhibitor), and Tylenol (acetaminophen) 650 mg every four hours as needed?

Management of Low Back Pain in a Breast Cancer Patient with Disc Herniation

Initial Assessment and Recommendation

Physical therapy consultation is the most appropriate next step for this 65-year-old breast cancer patient with low back pain and mild disc herniation at L4-L5. 1, 2

Rationale for Physical Therapy Referral

The patient presents with:

• Low back pain with positive straight leg test on the right
• MRI showing mild disc herniation at L4-L5
• No evidence of metastatic disease in the spine
• No neurological deficits beyond the positive straight leg test

This clinical picture is consistent with non-malignant disc herniation causing radicular symptoms, which aligns with the American College of Physicians guidelines recommending non-invasive therapies as first-line treatment 1.

Why Physical Therapy is Preferred:

1. Evidence of Non-Malignant Cause: MRI confirms mild disc herniation and specifically rules out metastatic disease or leptomeningeal spread 2.

2. Appropriate First-Line Treatment: For non-specific low back pain with radicular symptoms, conservative management including physical therapy is recommended before considering more invasive options 1, 2.

3. Positive Straight Leg Test: This test has high sensitivity (92%) for lumbar disc herniation 3, confirming the disc herniation is likely the source of symptoms.

4. No Red Flags: The patient has no neurological deficits that would necessitate urgent surgical intervention 1, 2.

Alternative Options and Why They're Not Preferred

Opioid Therapy (Oxycodone)

• Not recommended as first-line for non-malignant back pain
• The British Pain Society recommends avoiding opioids for acute low back pain without severe symptoms 2
• Current pain management with acetaminophen should be optimized before escalating to opioids

Orthopedic Surgical Consultation

• Surgery is typically reserved for patients who fail conservative management
• Guidelines suggest referring patients with non-specific low back pain for surgical evaluation only after 3 months of failed non-surgical interventions 1
• The patient has not yet tried conservative measures like physical therapy

Discontinuing Anastrazole

• No evidence suggests anastrazole is causing or exacerbating the disc herniation
• Discontinuing cancer treatment without clear indication could compromise oncologic outcomes
• The MRI confirms a mechanical cause (disc herniation) rather than medication side effect

Recommended Treatment Approach

1. Initial Physical Therapy Evaluation and Treatment:

   • Focus on active interventions rather than passive modalities 2
   • Include exercises to improve core strength and spinal stability
   • Incorporate pain management techniques and proper body mechanics

2. Optimize Current Pain Management:

   • Continue acetaminophen as currently prescribed
   • Consider adding an NSAID if not contraindicated (with caution due to cancer history) 2
   • Avoid immediate escalation to opioids

3. Follow-up and Monitoring:

   • Reassess after 4-6 weeks of physical therapy
   • If symptoms persist despite adequate physical therapy, consider:
     • Epidural steroid injection 4
     • Orthopedic or neurosurgical consultation if symptoms are severe or progressive 1

Important Considerations

• Cancer History: While the patient has metastatic breast cancer to the liver, the spine MRI specifically ruled out metastatic disease as the cause of back pain

• Age-Related Factors: At 65 years old, degenerative disc changes are common and often respond well to conservative management

• Medication Interactions: When considering additional pain medications, be mindful of potential interactions with anastrazole and other current medications

Physical therapy represents the most evidence-based, conservative approach for this patient with confirmed non-malignant disc herniation and no neurological deficits beyond the positive straight leg test.