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Approach to the Patient with Cancer

Oncology and Hematology | Part 4 | Section 1 Neoplastic Disorders · Part 4 – Oncology: Solid Tumors · Chapter 73


Key Clinical Points

  1. Biopsy is mandatory for cancer diagnosis; exception: Hepatocellular Carcinoma (HCC) can be diagnosed via CT/MRI perfusion patterns.
  2. Staging is essential: Clinical staging (physical exam, imaging) vs. Pathologic staging (surgical resection, lymph node biopsy).
  3. TNM System: T (Tumor size), N (Nodes), M (Metastasis); stages I–IV based on permutations of these factors.
  4. Physiologic reserve assessment (Karnofsky Performance Index or ECOG Performance Scale) is critical for predicting treatment tolerance and determining intent (Curative vs. Palliative).
  5. Depression screening is critical: Incidence ≈ 25%; treat with SSRIs (fluoxetine 10–20 mg/d, sertraline 50–150 mg/d) or TCAs (amitriptyline 50–100 mg/d, nortriptyline 25–150 mg/d).
  6. RECIST Criteria: Complete response (disappearance of disease), Partial response (>50% reduction), Stable disease, Progressive disease (>25% increase).
  7. Tumor Markers are used for monitoring response, not for primary diagnosis (e.g., CEA, CA-125, PSA).
  8. Multidisciplinary team approach: Medical oncologists, surgical oncologists, radiation oncologists, nurses, pharmacists, and social workers.
  9. Follow-up: Historically monthly for 6–12 months; current guidelines emphasize history/physical as primary investigations.
  10. Global Disparities: Lung cancer is the leading cause of death worldwide; other cancers (liver, cervical, esophageal) are more prevalent in less developed countries.

1. DEFINITION & OVERVIEW

Core Pathology: Cancer represents a breakdown of cellular cooperation and programmed death mechanisms. • Key Features: ◦ Cancer cells evade normal regulatory controls → uncontrolled proliferation. ◦ Patients experience profound psychological impact due to perceived bodily invasion. ◦ Unlike organ-specific diseases, cancer disrupts self-image and social roles. ◦ The disease's evolutionary analogy mirrors natural selection favoring malignant traits. • Clinical Context: ◦ Mortality: Median survival for pancreatic cancer equals that of aortic stenosis with CHF (≈ 8 months). ◦ Prevalence: 2.001 million new cases diagnosed annually in the US; 611,720 cancer-related deaths annually. ◦ Success Rate: Two-thirds of patients achieve cure with current therapies.

1.1 Magnitude of the Problem

Global Burden: 20 million new cases and 9.7 million deaths estimated globally in 2022. • Primary Cause: Lung cancer is most common (18.4% of all cancers) and leading cause of death (25.3% of cancer deaths).


Global Trends: ◦ Lung cancer: 18.4% of all cancers; 25.3% of deaths. ◦ Regional Disparities: Asia accounts for 59.2% of population but 46% of cases. • Modifiable Risk Factors (>30% of global burden): ◦ Smoking (18.1%), Alcohol (5.7%), Obesity (5.6%), Physical inactivity (3.2%). • Age as Primary Driver: ◦ 58% of cases occur in >65 years. ◦ Lifetime cancer risk: 40.5% for men, 38.9% for women. ◦ Age-specific incidence: - <50: 1/29 men, 1/19 women - 50–59: 1/15 men, 1/17 women - 60–69: 1/6 men, 1/10 women - ≥70: 1/3 men, 1/4 women

2.1 Regional and Demographic Distribution

Developed Countries: Higher incidence of lung (2 imes), breast (3 imes), prostate (2.5 imes), colorectal (3 imes). • Less Developed Countries: Higher rates of liver (2 imes), cervical (2 imes), esophageal (2–3 imes). • Africa: Cervical, breast, and liver cancers dominate. • Asia: Stomach cancer incidence is 2 imes higher than in North America. • Racial/Ethnic Disparities: Black patients have twice the mortality for prostate, stomach, and uterine corpus cancers. • Table 73-1 Summary: Highlights high incidence of Prostate (29%) and Breast (32%); Lung cancer is a leading cause of death for both sexes (20% men, 21% women).


3. ETIOLOGY & PATHOPHYSIOLOGY

Drivers: Complex interactions between genetic and environmental factors. • Risk Factors: 9 modifiable risk factors account for >30% of global burden (Smoking, Alcohol, Obesity, Physical inactivity). • Molecular Features: ◦ Genetic heterogeneity: Tumors with identical morphology may have distinct molecular profiles. ◦ Proliferation markers: Ki-67 correlates with aggressive behavior. • Host Factors: Influence treatment response through drug metabolism genes.


4. CLINICAL MANIFESTATIONS

Clinical Evaluation: ◦ History: Identify occupational exposures, family cancer syndromes, and paraneoplastic symptoms. ◦ Physical Exam: Identify local tumor effects (masses, lymphadenopathy) and systemic signs (weight loss, fatigue). • Staging Framework: ◦ Clinical staging: Imaging (CT, MRI), physical exam. ◦ Pathologic staging: Surgical findings, histology. • TNM System: ◦ T: Tumor size (T1–4) ◦ N: Node involvement (N0–N3) ◦ M: Metastasis (M0–M1)

4.1 Physiologic Reserve Assessment

Purpose: Predicts treatment tolerance and determines intensity of therapy. • Karnofsky Performance Index (Table 73-4): ◦ 100: Normal; no complaints; no evidence of disease. ◦ 90: Able to carry on normal activity; minor signs/symptoms. ◦ 70: Cares for self; unable to carry on normal activity or do active work. • ECOG Performance Scale (Table 73-5): ◦ Grade 0: Fully active, no restrictions. ◦ Grade 1: Restricted in physically strenuous activity; ambulatory; light/sedentary work. ◦ Grade 2: Ambulatory; capable of all self-care; unable to carry out any work activities. Up and about >50% of waking hours. ◦ Grade 3: Limited self-care; confined to bed or chair >50% of waking hours. ◦ Grade 4: Completely disabled; cannot carry on any self-care; totally confined to bed/chair. ◦ Grade 5: Dead.


5. DIFFERENTIAL DIAGNOSIS

Diagnostic Requirement: Tissue confirmation is mandatory for most cancers. • Exception: Hepatocellular carcinoma (HCC) can be diagnosed via CT/MRI perfusion patterns. • Tumor Markers (Table 73-6): Used for monitoring response, NOT primary diagnosis. ◦ α-Fetoprotein: Hepatocellular carcinoma, gonadal germ cell tumor. ◦ Catecholamines: Pheochromocytoma. ◦ Carcinoembryonic antigen: Adenocarcinomas of the colon, pancreas, lung, breast, ovary. ◦ Neuron-specific enolase: Small-cell cancer of the lung, neuroblastoma. ◦ Prostate-specific antigen (PSA): Prostate cancer. ◦ CA-125: Ovarian cancer, some lymphomas. ◦ CD30: Hodgkin’s disease, anaplastic large-cell lymphoma. ◦ CD25: Hairy cell leukemia, adult T-cell leukemia/lymphoma. • Clinical Utility of Specific Markers: ◦ CEA: Elevated in 70% of colon cancers; normal <2.5 ng/mL. ◦ CA-125: Elevated in 80% of ovarian cancers; normal <35 U/mL. ◦ PSA: Elevated in 90% of prostate cancers; normal <4 ng/mL. • Limitations: Non-specificity, false positives in benign conditions (e.g., CA-125 in peritonitis or pregnancy).


6. INVESTIGATIONS & DIAGNOSIS

Staging Framework: ◦ Clinical staging: Physical exam and imaging (CT, MRI). ◦ Pathologic staging: Surgical findings and histology. • Neoadjuvant Therapy: Pre-surgery treatment indicated by 'y' in staging; applicable for breast, head/neck, and lung cancers. • TNM Classification: ◦ T: Tumor size (T1–4) ◦ N: Node involvement (N0–N3) ◦ M: Metastasis (M0–M1) • Staging Algorithm (Figure 73-5): 1. Clinical Staging → Physical exam & Imaging. 2. Pathologic Staging → Surgical findings & Histology. 3. TNM Integration → Determine T, N, and M status. 4. Treatment Intent Determination → Based on ECOG/Karnofsky scores. • Age-Specific Patterns (Table 73-2): ◦ <20: CNS, leukemia dominate. ◦ 20–39: Breast (females), testicular (males) common. ◦ 40–49: Colorectal (both sexes), lung (males). ◦ >80: Lung, prostate (males); breast, colorectal (females).

6.1 Response Assessment

RECIST Criteria: ◦ Complete response: Disappearance of disease. ◦ Partial response: >50% reduction. ◦ Stable disease. ◦ Progressive disease: >25% increase.


7. TREATMENT STRATEGIES

  1. Multidisciplinary Team Assembly:
  2. Medical oncologist (chemotherapy, immunotherapy).
  3. Surgical oncologist (resection, biopsy).
  4. Radiation oncologist (external beam, brachytherapy).
  5. Palliative care specialist (symptom management).
  6. Social worker (support services).
  7. Treatment Intensity Determination:
  8. ECOg 0–1 → Curative intent possible.
  9. ECOG ≥ 2 → Palliative focus.
  10. Depression Management:
  11. Screening: Use PHQ-9; score ≥ 10 indicates depression.
  12. Treatment (SSRIs): Fluoxetine 10–20 mg/d, Sertraline 50–150 mg/d.
  13. Treatment (TCAs): Amitriptyline 50–100 mg/d, Nortriptyline 25–150 mg/d.
  14. Monitoring: Watch for serotonin syndrome.
  15. Follow-up Protocol:
  16. Historical: Monthly for 6–12 months → less frequent.
  17. Current: History and physical are primary investigations.

Treatment Complications

Chemotherapy: Myelosuppression, neuropathy. - Radiation: Dermatitis, fibrosis. - Surgery: Infection, anastomotic leak. - Immunotherapy: Immune-related adverse events (pneumonitis, colitis).


8. PROGNOSIS & COMPLICATIONS

Prognostic Factors: ◦ Stage: Strongest predictor of survival. ◦ Performance Status: ECOG ≥ 2 correlates with <6-month survival. • Late Complications: ◦ Radiation: Secondary malignancies, fibrosis. ◦ Chemotherapy: Cardiotoxicity, secondary leukemia. ◦ Surgery: Chronic pain, functional impairment.


9. SPECIAL CONSIDERATIONS

Geriatric Assessment: Comprehensive evaluation of frailty, cognition, and comorbidities to tailor treatment. • Palliative Care: Early referral improves quality of life. • Global Disparities: Address socioeconomic barriers to treatment access.


10. KEY PEARLS & CLINICAL TRAPS

Biopsy Rule: Never diagnose cancer without tissue biopsy (except HCC). • Monitoring vs. Diagnosis: Tumor markers are monitoring tools, not diagnostic tests. • Response Criteria: Use RECIST for objective response assessment. • Performance Status: The best predictor of treatment tolerance and survival. • Multidisciplinary Care: Standard of care involving medical, surgical, and radiation oncology.


Reference Tables

TABLE 73-1 Distribution of Cancer Incidence and Deaths for 2021 SITES Cancer Incidence Prostate Lung Colorectal Bladder…

Harrison's 22e, p.497

MALE FEMALE
SITES % NUMBER SITES % NUMBER
Cancer Incidence
Prostate 29 299,010 Breast 32 310,720
11 116,310 Lung 12
Colorectal 8 81,540 Colorectal 7 71,270
6 63,070 Endometrial 7
Melanoma 6 59,170 Melanoma 4 41,470
5 52,380 Lymphoma 4
Lymphoma 4 44,590 Pancreas 3 31,910
4 41,510 Thyroid 3
Leukemia 4 36,450 Kidney 3 29,230
3 34,530 Leukemia 3
All others 19 200,520 All others 21 207,440
100 1,029,080 All sites 100
Cancer Deaths
Lung 20 65,790 Lung 21 59,280
11 35,250 Breast 15
Colorectal 9 28,700 Pancreas 8 24,480
8 25,270 Colorectal 8
Liver 6 19,120 Endometrial 5 13.250
4 13,640 Ovary 4
Esophagus 4 12,880 Liver 3 10,720
4 12,290 Leukemia 3
Lymphoma 4 11,780 Lymphoma 3 8,360
3 10,690 CNS 3
All others 27 87,390 All others 26 75,4330
100 322,800 All sites 100

TABLE 73-2 The Five Leading Primary Tumor Sites for Patients Dying of Cancer Based on Age and Sex in 2018 RANK 1 2 3 4 5

Harrison's 22e, p.500

RANK SEX ALL AGES AGE, YEARS
UNDER 20 20–39 40–49 50-64 65–79 >80
1 M Lung CNS Colorectal Colorectal Lung Lung Lung
F Lung CNS Breast Breast Lung Lung Lung
M
F
Prostate
Breast
Leukemia
Leukemia
CNS
Cervix
Lung
Colorectal
Colorectal
Breast
Prostate
Breast
3 M Colorectal Bone sarcoma Leukemia CNS Pancreas Liver Colorectal
F Colorectal Soft tissue sarcoma Colorectal Lung Colorectal Pancreas Colorectal
M
F
Pancreas
Pancreas
Soft tissue sarcoma
Bone sarcoma
Testis
CNS
Pancreas
Cervix
Liver
Pancreas
Colorectal
Colorectal
5 M Liver Lymphoma Lymphoma Esophagus Esophagus Liver Pancreas
F Ovary Kidney Leukemia Ovary Ovary Ovary Leukemia

TABLE 73-3 Cancer Incidence and Mortality in Racial and Ethnic Groups, United States, 2016–2020 SITE Incidence per…

Harrison's 22e, p.501

SITE SEX WHITE BLACK ASIAN/PACIFIC
ISLANDER
AMERICAN INDIANa HISPANIC
Incidence per 100,000 Population
All M 511.2 533.9 299.0 504.1 377.2
F 499.3 409.9 307.3 465.5 351.3
134.9 129.6 104.6 115.5
Colorectal M 40.4 48.8 33.4 57.8 38.2
F 30.5 35.0 23.7 43.7 27.2
M
F
24.3
12.1
26.4
13.7
11.6
5.5
43.9
23.9
Liver M 11.2 17.0 18.4 27.3 20.4
F 4.2 5.5 6.7 12.3 8.4
M
F
765.7
54.8
72,4
45.8
40.8
28.1
67.2
58.6
Prostate 110.7 186.1 60.9 91.9 90.9
M
F
7.1
3.4
13.0
7.4
11.8
6.9
13.1
7.8
Cervix 7.2 8.6 6.0 11.4 9.7
27.9 28.9 21.7 30.4
Deaths per 100,000 Population
All M 183.3 217.4 111.6 221.6 130.2
F 133.6 150.2 83.7 157.9 93.5
19.7 27.8 11.8 21.1
Colorectal M 15.5 22.4 11.0 23.1 13.6
F 11.1 14.4 7.8 16.0 8.5
M
F
5.3
2.3
5.2
2.2
2.4
1.0
9.9
4.2
Liver M 8.5 13.0 12.6 19.9 13.1
F 3.7 4.8 5.2 8.8 6.0
M
F
44.9
32.9
51.3
28.0
25.9
15.6
52.3
37.0
Prostate 17.9 37.9 8.7 22.5 15.4
M
F
2.9
1.5
7.2
3.5
6.0
3.7
7.7
4.1
Cervix 2.0 3.3 1.7 2.3 2.5
4.6 9.1 3.5 4.9

TABLE 73-4 Karnofsky Performance Index

Harrison's 22e, p.503

PERFORMANCE
STATUS
FUNCTIONAL CAPABILITY OF THE PATIENT
100 Normal; no complaints; no evidence of disease

TABLE 73-5 The Eastern Cooperative Oncology Group (ECOG) Performance Scale ECOG grade 0: Fully active, able to carry on…

Harrison's 22e, p.503

ECOG grade 0: Fully active, able to carry on all predisease performance without
restriction
ECOG grade 1: Restricted in physically strenuous activity but ambulatory and
able to carry out work of a light or sedentary nature, e.g., light housework,
office work
ECOG grade 2: Ambulatory and capable of all self-care but unable to carry out
any work activities. Up and about >50% of waking hours
ECOG grade 3: Capable of only limited self-care, confined to bed or chair >50% of
waking hours
ECOG grade 4: Completely disabled. Cannot carry on any self-care. Totally
confined to bed or chair
ECOG grade 5: Dead
80 Normal activity with effort; some signs or symptoms of
disease
60 Requires occasional assistance but is able to care for most
needs
40 Disabled; requires special care and assistance
20 Very sick; hospitalization is necessary; active supportive
treatment is necessary
0 Dead

TABLE 73-6 Tumor Markers

Harrison's 22e, p.504

TUMOR
MARKERS
CANCER NONNEOPLASTIC
CONDITIONS
Hormones
Human chorionic
gonadotropin
Gestational trophoblastic disease,
gonadal germ cell tumor
Pregnancy
Medullary cancer of the thyroid
Catecholamines Pheochromocytoma
Oncofetal Antigens
Hepatocellular carcinoma,
gonadal germ cell tumor
Carcinoembryonic
antigen
Adenocarcinomas of the colon,
pancreas, lung, breast, ovary
Pancreatitis, hepatitis,
inflammatory bowel
disease, smoking
Enzymes
Prostate cancer
Neuron-specific
enolase
Small-cell cancer of the lung,
neuroblastoma
Lymphoma, Ewing’s sarcoma
Tumor-Associated Proteins
Prostate-specific
antigen
Prostate cancer Prostatitis, prostatic
hypertrophy
Myeloma
CA-125 Ovarian cancer, some lymphomas Menstruation,
peritonitis, pregnancy
Colon, pancreatic, breast cancer
CD30 Hodgkin’s disease, anaplastic
large-cell lymphoma
Hairy cell leukemia, adult T-cell
leukemia/lymphoma