Approach to Carcinoma Penis 2

Carcinoma Penis

Author

  • Deepak K Thakur, Ms, MCh (Urology)

Contents

  • Relevant anatomy

  • History

  • Examination

  • Investigations

  • Staging

  • Decision making

  • Treatment options

  • Outcome

  • Follow up

Relevant Anatomy

  • Penile Anatomy:

    • Superficial and deep dorsal vein

    • Dorsal artery

    • Fascicles of dorsal nerve

    • Skin and superficial (dartos) fascia

    • Deep (Buck) fascia

    • Subtunical space

    • Cavernosal artery

    • Erectile tissue

    • Tunica albuginea: outer longitudinal layer, inner circular layer, corpus spongiosum

Vascular Supply

  • Arteries:

    • Internal pudendal artery

    • Cavernous artery

    • Bulbourethral artery

    • Circumflex artery

    • Dorsal artery

  • Veins:

    • Deep dorsal vein

    • Circumflex vein

    • Periprostatic vein

    • Internal pudendal vein

    • External iliac vein

    • Cavernous vein

    • Bulbar vein

    • Subtunical venous plexus

Lymphatic Drainage

  • Lymphatics of the prepuce and skin = superficial inguinal nodes

  • Lymphatics of the glans and corporeal bodies = superficial nodes

  • Drainage pathway: superficial nodes > deep inguinal nodes > pelvic nodes (external, internal iliac, and obturator nodes)

  • Multiple cross-connections exist leading to bilateral drainage to both inguinal areas

Risk Factors

  • Phimosis

  • Chronic penile inflammations:

    • Balanoposthitis

    • Lichen sclerosus

  • Human Papillomavirus (HPV) types 16 & 18

  • UV-A therapy

  • Multiple sexual partners

  • Smoking

  • Poor hygiene

  • Low socioeconomic status

Pathology

Premalignant Conditions

  • ~1/3 malignancy risk

  • Conditions include:

    • Intraepithelial neoplasia grade III

    • Giant condylomata (Buschke-Löwenstein)

    • Erythroplasia of Queyrat

    • Bowen’s disease

    • Paget’s disease (intradermal adenocarcinoma)

Presentation

  • Commonly affects elderly males

  • Typical presenting symptom: lesion on the penis

  • Associated symptoms:

    • Bleeding

    • Weakness

    • Weight loss

    • Fatigue

    • Systemic malaise due to chronicity

Lesion Characteristics

  • May appear as:

    • Shallow erosion

    • Deeply excavated ulcer with elevated or rolled-in edges

  • Phimosis may obscure lesions

  • Symptoms: erosion through the prepuce, foul odor, and discharge with or without bleeding

Tumor Distribution

  • Common locations for tumors:

    • Glans (48%)

    • Prepuce (21%)

    • Coronal sulcus (6%)

    • Shaft (<2%)

  • Assessment of:

    • Size

    • Location

    • Fixation

    • Involvement of corporeal bodies

Clinical Examination

  • Inspect base of penis and scrotum for extension

  • Rectal and bimanual examination to assess perineal involvement and pelvic mass

  • Extensive bilateral inguinal palpation for adenopathy is crucial

Diagnosis

  • Delay in Medical Care: 15% to 50% of patients seek care after a year or more

  • Requirements before therapy:

    • Confirmation of diagnosis

    • Assessment of invasion and histologic grade

  • Biopsy Procedures: May be separate from definitive treatment; a dorsal slit may be necessary

  • Diagnosis Indicators: Anemia, leucocytosis, hypoalbuminemia, azotemia, hypercalcemia

Node Assessment

  • Techniques:

    • Fine needle aspiration cytology

    • Sentinel lymph node biopsy

    • Dynamic sentinel node biopsy

    • Superficial & modified complete inguinal dissection

Radiological Assessment

  • Methods:

    • Penile Ultrasound (USG)

    • Contrast-enhanced CT (CECT)

    • MRI

    • Lymphotropic nanoparticle-enhanced MRI (LNMRI)

    • FDG-PET/CT

Sensitivity of Diagnostic Methods

  • FNAC: 93% for palpable nodes; 71% for non-palatable nodes

  • DSNB: Lower morbidity; sensitivity of 82%, false-negative rate of 18%

Surgical Approaches

  • Superficial & modified inguinal dissection: Effective in identifying microscopic metastases in clinically normal inguinal findings

Imaging Techniques

  • USG: Detects 100% of corpus cavernosum invasion; inaccurate in 26% of physical exams

  • MRI: Sensitive in detecting corporal invasion

  • LNMRI: Highly sensitive for micrometastasis; effective for nodes <1 cm

Minimal Diagnostic Criteria

  • Primary Tumor (T): Clinical examination, incisional/excisional biopsy for grade and invasion assessment

  • Regional Lymph Nodes (N): Clinical examination, CT for palpable adenopathy, superficial inguinal node dissection as indicated

  • Distant Metastases (M): Clinical examination, chest radiographs, biochemical determinations, MRI, and bone scans

AJCC Staging of Penile Cancer

Primary Tumor (T)

  • TX, TO, Tis, Ta, T1a, T1b, T2, T3, T4

Lymph Nodes (N)

  • NX, PNX, NO, N1, N2, N3, pN3

Distant Metastasis (M)

  • M0, M1

Stage Grouping

  • Stage 0: Tis, Ta, N0, M0

  • Stage I: T1a, N0, M0

  • Stage II: T1b, T2, N0, M0; T3, N0, M0

  • Stage IIIa: T1-3, N1, M0

  • Stage IIIb: T1-3, N2, M0

  • Stage IV: T4, Any N, M0; Any T, N3, M0; Any T, Any N, M1

Treatment Options

Primary Tumor Treatment

  • Organ-preserving measures

  • Limited excision strategies:

    • Topical therapy (5-fluorouracil for Tis)

    • Mohs micrographic surgery

    • Laser ablation

    • Penile amputation

    • Radiation therapy

Mohs Micrographic Surgery

  • Layer-by-layer excision with microscopic examination; relevant for CIS & small tumors

Laser Ablation

  • CO2, argon, Nd:YAG, and KTP lasers; effectively treats T1 tumors

  • Recurrence rates variable; recurrences require wide local excision or partial amputation

Penile Amputation

  • Indicated for deeply invasive or high-grade tumors; tumors >4 cm, grade 3 lesions, or invading structures

Treatment of Inguinal Metastasis

  • Presence and extent of metastasis crucial for prognosis

  • Lymphadenectomy can be curative for many cases

Risk Assessment for Nodes

  • Palpable nodes: indication for intervention

  • Non-palpable nodes categorized into risk groups:

    • Low risk: CIS, Ta

    • Intermediate risk: T1, grade 1 and 2

    • High risk: pT2

Low & Intermediate Risk Group Protocol

  • Physical examination of lymphatics, observation, antibiotics if needed, further testing as indicated

High-Risk Group Protocol

  • Surgical approaches more aggressive, including bilateral dissection, FNAC, and imaging studies

Treatment for Metastatic Disease

  • Strategies depend on the presence and mobility of nodal metastases; might involve:

    • Induction chemotherapy

    • Surgical resection if responsive

    • Palliative options if progressive

Radiation Therapy

  • Types:

    • External beam radiation therapy (EBRT)

    • Brachytherapy

  • Prior circumcision often necessary before treatment

Efficacy of EBRT

  • 60 Gy to 74 Gy delivered over 5 to 7.5 weeks

  • Local control rates: 45-70%, preservation rates: 50-65%

Efficacy of Brachytherapy

  • Isotopes like radium-226 and iridium-192; superior local control rates of 70% to 87%

Chemotherapy

  • Indications: advanced, recurrent disease

  • Single agent (Cisplatin, Bleomycin, Methotrexate) and combination therapies

  • Efficacy rates from studies demonstrate variable response

Follow-up Protocol

  • For low-risk group: Annual follow-ups; shorter intervals initially

  • For high-risk group: More frequent assessments and imaging as required.