Overview

Colorectal cancer (CRC) is a major global health burden due to its high incidence and mortality. When detected early, CRC is highly curable, with reported cure rates of up to 90%. A large proportion of cases are preventable through effective screening and established cancer prevention strategies.

Advances in screening, molecular diagnostics, biomarker development, and multimodal oncologic treatment have significantly improved detection and survival outcomes in CRC.

Principle of Care in Germany

In Germany, CRC management is based on personalized, stage-adapted treatment planning, which is the cornerstone of modern oncologic care. Each patient receives an individualized strategy based on tumor location, histology, and disease stage.

Accurate histopathological diagnosis and precise staging are essential for optimal treatment selection and are central to the INDID Telemedicine workflow.

All cases are reviewed in multidisciplinary tumor boards at partner centers in Germany. INDID Telemedicine coordinates diagnostic completion and resolves issues related to incomplete or suboptimal pathology and imaging from initial evaluations.

1. Initial Staging and Risk Assessment

CRC staging defines disease extent (Stages I–IV) based on:

• Depth of tumor invasion 
• Lymph node involvement 
• Presence of distant metastases 

Remote staging approach (INDID Telemedicine)

Most international patients can complete full staging in their home country with coordinated support from INDID Telemedicine. Travel to Germany is not required for diagnostic completion.

Required baseline evaluation:

• Medical and family history 
• Physical examination 
• Blood tests (CBC, liver and renal function, tumor markers including CEA) 

Endoscopy:

• Colonoscopy is the primary diagnostic procedure 
• Video documentation should be provided when available 

Pathology:

• Diagnosis is usually confirmed via colonoscopic biopsy 
• Histopathological reports are reviewed centrally 
• In selected cases, tissue blocks (paraffin/frozen) may be reassessed in German reference pathology laboratories 

Imaging:

• CT scan (chest/abdomen/pelvis) for staging 
• MRI pelvis is essential in rectal cancer for:
  • Mesorectal fascia assessment 
  • Sphincter involvement evaluation 
  • Surgical planning 
• PET-CT or ultrasound may be used in selected cases 

High-quality imaging is essential for accurate staging and treatment planning. If necessary, repeat imaging may be recommended.

2. Multidisciplinary Treatment Planning

All cases are reviewed in multidisciplinary tumor boards involving:

• Gastrointestinal surgeons 
• Medical oncologists 
• Radiation oncologists 
• Radiologists 
• Pathologists 
• Additional specialists (urology, gynecology, genetics) when needed 

Treatment decisions are individualized based on tumor stage, biology, and patient condition.

3. Treatment of Colorectal Cancer

Surgery

• Primary curative treatment for localized CRC (Stage I–III) 
• May also be considered in selected metastatic cases (liver/lung metastases) 
• Decision-making is individualized through tumor board discussion 

Rectal cancer surgery:

• Local excision for selected early lesions 
• Low anterior resection (LAR) or abdominoperineal resection (APR) for invasive disease 
• Total mesorectal excision (TME) is standard for oncologic control 
• Neoadjuvant radiotherapy is used for low rectal tumors to improve resectability and sphincter preservation 

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Radiotherapy

• Neoadjuvant radiotherapy: tumor downstaging 
• Adjuvant radiotherapy: local control in rectal cancer 
• Standard component of multimodal rectal cancer therapy 

Chemotherapy

• Adjuvant therapy in node-positive colon cancer 
• Neoadjuvant therapy increasingly used in rectal cancer 
• May also be used in metastatic disease to prolong survival and control disease progression 

Targeted Therapy

Used in metastatic CRC based on molecular profile:

• Bevacizumab 
• Cetuximab / Panitumumab 
• Ramucirumab 
• Regorafenib 
• Trifluridine/tipiracil (TAS-102) 

Selection depends on RAS/BRAF mutation status and tumor biology.

Immunotherapy

• Effective in mismatch repair-deficient (dMMR) / microsatellite instability-high (MSI-H) tumors 
• Agents include pembrolizumab and nivolumab 
• Tumor molecular testing is required before initiation 

Proton Beam Therapy

May be considered in selected cases where tumor location is adjacent to critical structures, particularly in younger patients or complex anatomical situations.

4. Follow-Up After Treatment

Most recurrences occur within 2–3 years after surgery; therefore, structured follow-up is essential.

Standard follow-up schedule:

• Every 6 months for 2 years:
  • Clinical examination 
  • Blood tests 
  • Tumor markers (CEA) 
  • Imaging (CT abdomen ± pelvis) 
• At least two CT scans of chest/abdomen/pelvis within first 3 years 
• Colonoscopy:
  • Within 12 months after surgery (if not performed earlier) 
  • Then every 5 years if normal 

Follow-up is individualized based on risk profile and tumor stage.

Telemedicine Follow-Up (INDID)

Patients treated in Germany typically do not need to return for routine follow-up visits. INDID Telemedicine provides structured remote monitoring and coordination with local physicians.

References

Cervantes, A., Adam, R., Roselló, S., Arnold, D., Normanno, N., Taïeb, J., et al. (2023). Metastatic colorectal cancer: ESMO Clinical Practice Guideline for diagnosis, treatment and follow-up. Annals of Oncology, 34(1), 1032.  https://doi.org/10.1016/j.annonc.2022.10.003   Glynne-Jones, R., Wyrwicz, L., Tiret, E., Brown, G., Rödel, C., Cervantes, A., & Arnold, D. (2017). Rectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Annals of Oncology, 28, iv22–iv40. https://doi.org/10.1093/annonc/mdx224