The Residual Cancer Burden (RCB) system is a standardized method for quantifying the extent of residual disease in the breast after neoadjuvant therapy (treatment given before surgery) for breast cancer. It aims to provide a more objective and reproducible assessment of treatment response than subjective pathological assessments alone. The RCB score helps in predicting prognosis, informing treatment decisions, and standardizing research across different institutions.
How the RCB Score is Calculated
The RCB score is calculated based on three key pathological parameters obtained after surgery:
Tumor Volume: The size of the primary tumor remaining after neoadjuvant therapy.
Nodal Involvement: The number of lymph nodes positive for cancer after neoadjuvant therapy.
Distant Metastasis: Whether cancer has spread to distant parts of the body (typically assessed clinically, but for the basic RCB calculation, we'll focus on the primary tumor and lymph nodes).
The standard RCB calculation involves a formula that combines these factors. For simplicity in this online calculator, we are using a simplified model that focuses on tumor volume and a treatment response score, reflecting the *degree* of tumor reduction. A more complete RCB calculation would also incorporate lymph node status.
Simplified Calculation Logic
This calculator uses a simplified approach to estimate an "RCB Score" as a representation of treatment effectiveness and remaining disease. The core idea is to assess how much of the initial tumor burden is left relative to the treatment's effectiveness.
Initial Tumor Volume (cm³): The size of the tumor before neoadjuvant therapy.
Residual Tumor Volume (cm³): The size of the tumor found after surgery, post-treatment.
Treatment Response Score (%): A subjective or objective measure of how well the treatment worked, where 100% means complete response and 0% means no response.
A lower RCB score generally indicates a better treatment response and less residual disease, suggesting a better prognosis. Conversely, a higher score suggests a less effective treatment and more residual disease.
Interpreting the RCB Score
The full RCB system categorizes patients into four groups:
RCB 0: Complete pathologic response.
RCB I: Minimal residual disease.
RCB II: Moderate residual disease.
RCB III: Extensive residual disease.
This calculator provides a numerical score that can be interpreted in the context of these categories. A lower score suggests a better outcome (closer to RCB 0 or I), while a higher score indicates poorer outcomes (closer to RCB II or III).
Use Cases
Prognostic Assessment: Helps predict the likelihood of cancer recurrence or spread.
Treatment Evaluation: Assists in determining the effectiveness of neoadjuvant therapies.
Clinical Trials: Standardizes the measurement of treatment response in research settings.
Personalized Medicine: Guides decisions on adjuvant therapy (treatment after surgery) based on the degree of response.
Disclaimer: This calculator is for informational purposes only and does not constitute medical advice. It uses a simplified model. Always consult with a qualified healthcare professional for diagnosis and treatment recommendations.
function calculateRCB() {
var tumorVolume = parseFloat(document.getElementById("tumorVolume").value);
var residualVolume = parseFloat(document.getElementById("residualVolume").value);
var treatmentResponseScore = parseFloat(document.getElementById("treatmentResponseScore").value);
var resultDiv = document.getElementById("result");
// Input validation
if (isNaN(tumorVolume) || tumorVolume <= 0) {
resultDiv.innerHTML = "Please enter a valid initial tumor volume (greater than 0).";
resultDiv.style.backgroundColor = "#ffc107"; // Warning yellow
return;
}
if (isNaN(residualVolume) || residualVolume < 0) {
resultDiv.innerHTML = "Please enter a valid residual tumor volume (0 or greater).";
resultDiv.style.backgroundColor = "#ffc107";
return;
}
if (isNaN(treatmentResponseScore) || treatmentResponseScore 100) {
resultDiv.innerHTML = "Please enter a valid treatment response score between 0 and 100.";
resultDiv.style.backgroundColor = "#ffc107";
return;
}
if (residualVolume > tumorVolume) {
resultDiv.innerHTML = "Residual volume cannot be greater than initial tumor volume.";
resultDiv.style.backgroundColor = "#ffc107";
return;
}
// Simplified RCB calculation: (Residual Volume / Initial Volume) * (100 – Response Score)
// This provides a relative measure of remaining burden considering response effectiveness
var rcbScore = (residualVolume / tumorVolume) * (100 – treatmentResponseScore);
// Cap the score if necessary, although the formula should ideally keep it reasonable
if (rcbScore 100) rcbScore = 100; // Can happen if response score is very low and residual is high
resultDiv.innerHTML = "RCB Score: " + rcbScore.toFixed(2) + "";
resultDiv.style.backgroundColor = "var(–success-green)"; // Reset to success green
}