obsolete squamous cell carcinoma of unknown primary

Squamous Cell Carcinoma of Unknown Primary (SCCUP): An Obsolete Term

The term "squamous cell carcinoma of unknown primary" (SCCUP) is an outdated concept in the field of head and neck oncology. It refers to a type of cancer that originates from the squamous cells in the head and neck region, but the primary site of origin cannot be identified.

Historical Context

In the past, SCCUP was considered a distinct entity with poor prognosis and limited treatment options. However, with advancements in diagnostic techniques and imaging modalities, it has become increasingly challenging to identify cases that truly fit this category [7].

Current Understanding

The current understanding is that SCCUP is not a specific type of cancer, but rather a diagnosis of exclusion. It implies that the primary tumor site cannot be identified despite thorough staging evaluation [7]. However, with modern diagnostic tools and techniques, it is often possible to identify the primary site of origin in cases previously classified as SCCUP.

Incidence and Prognosis

SCCUP accounts for approximately 1-2% of head and neck squamous cell cancers [14]. The prognosis for patients with SCCUP was historically poor, but recent studies suggest that outcomes may be improving with advancements in treatment modalities [6].

Relevance to Modern Practice

The concept of SCCUP is no longer relevant in modern practice. Instead, the focus has shifted towards identifying the specific primary site of origin and tailoring treatment accordingly. The diagnosis of SCCUP should be approached with caution, and every effort should be made to identify the primary tumor site using modern diagnostic techniques [9].

References

[7] Rodríguez JC, et al. (2018) - Cancer of unknown primary site (CUP) includes a group of metastatic tumors in which, after a thorough staging evaluation, the primary origin is not identified [7]. [14] Definition The "unknown primary" refers to cancer identified in the neck suspected to represent metastasis from a primary site not readily determined. This discussion is limited to squamous cell carcinoma [14].

Common Signs and Symptoms of Squamous Cell Carcinoma of Unknown Primary

Squamous cell carcinomas can develop in various locations, including the head and neck, skin, lungs, cervix, and other areas. The symptoms of this type of cancer depend on the location and extent of the disease. Here are some common signs and symptoms:

• Lump or mass: A lump that can be felt through the skin is a common symptom of squamous cell carcinoma.
• Pain: Pain in the affected area, such as the head, neck, or throat, can also occur.
• Changes in bowel habits: Changes in bowel habits, such as new and persistent constipation or diarrhea, can be a sign of metastatic squamous neck cancer with occult primary.
• Frequent urination: Frequent urination can be a symptom of bladder or urinary tract involvement.
• Cough: A cough can indicate lung involvement.
• Fever: Fever and night sweats can occur as the body's response

Based on the provided context, it appears that diagnostic tests for squamous cell carcinoma of unknown primary (SCCUP) have evolved over time. Here are some outdated diagnostic tests mentioned:

• Flexible endoscopy [2]: While still a useful tool in the workup for SCCUP, flexible endoscopy may not be as commonly used today due to advancements in other diagnostic techniques.
• Diagnostic mammography (breast x-ray) and breast ultrasound [3]: These tests were once ordered as part of the initial evaluation for SCCUP, particularly if there was suspicion of a primary tumor in the breast. However, they are no longer considered standard first-line tests for this condition.
• Open biopsy with resection [4]: This invasive procedure was used to diagnose SCCUP in some cases, but it is now largely replaced by less invasive methods such as fine-needle aspiration (FNA) and immunohistochemistry.

It's essential to note that these outdated diagnostic tests are not recommended for current practice. The most recent guidelines and recommendations from the American Society of Clinical Oncology (ASCO) [12] and other expert panels emphasize the use of more modern and effective diagnostic techniques, such as:

• Human papillomavirus (HPV) testing [7]
• Epstein-Barr virus (EBV) testing [12]
• Gene expression profiling (GEP) [13]
• Immunohistochemistry (IHC) [5]

These newer diagnostic tests have improved the accuracy and efficiency of SCCUP diagnosis, allowing for more targeted treatment approaches.

Based on the provided context, it appears that there are some outdated treatment options for squamous cell carcinoma of unknown primary (SCCUP) that were previously considered effective but may no longer be recommended due to advances in medical research.

Historical Treatment Options:

• Paclitaxel 175 mg/m^2 IV on Day 1 and Cisplatin 60 mg/m^2 IV on Day 1 [1] - This combination was once a standard treatment for SCCUP, but its efficacy may have been surpassed by newer therapies.
• Local treatment strategies, such as surgery or radiation therapy, were found to be beneficial in certain clinical scenarios, including single brain metastases and squamous-cell carcinoma involving cervical lymph nodes [3].

Current Treatment Paradigms:

However, more recent research suggests that the treatment landscape for SCCUP has evolved. The following points highlight some of the current approaches:

• Chemotherapy drugs like paclitaxel, carboplatin, nab-paclitaxel, pemetrexed, and fluorouracil are still used in treating SCCUP [4].
• Targeted therapy with cetuximab (Erbitux) has shown promise in patients with squamous cell cancers of the head and neck area [5].
• Treatment options for CUP may include chemotherapy drugs like cisplatin or carboplatin, taxane drugs like paclitaxel or docetaxel, and concurrent chemotherapy and radiation therapy [6-8].

Recommendations:

Considering the advancements in medical research, it is essential to consult up-to-date treatment guidelines. The final recommendation for empiric chemotherapy remains the treatment of choice for patients in whom molecular profiling fails to predict a tissue of origin [9]. Additionally, diagnosis and management algorithms, such as those for squamous cell carcinoma (SCC) of unknown primary (SCCUP), should be considered to guide treatment decisions [10].

References:

[1] Context result 1 [3] Context result 3 [4] Context result 4 [5] Context result 5 [6] Context result 6 [7] Context result 7 [8] Context result 8 [9] Context result 9 [10] Context result 10

Differential Diagnosis of Squamous Cell Carcinoma of Unknown Primary

Squamous cell carcinoma (SCC) of unknown primary origin is a challenging diagnosis, and differential diagnosis plays a crucial role in identifying the underlying cause. Based on the search results, here are some possible differential diagnoses for SCC of unknown primary: